Design of the Opel Bitter CD at Opel Design in Russelsheim, Germany

By Dick Ruzzin


Opel Design in November of 1971.

To understand the importance of Opel Design in the early seventies, it should be known that Opel produced more cars per year than Chrysler did in the United States. All of the design came out of one small building that employed about sixty people, including exterior design, interior design, design engineering, a special projects shop, and the fabrication shop.

In retrospect, for those designers who worked in big companies, this design assignment was an amazing one-in-a-million opportunity for everyone involved; it would never happen again in their entire career.

The design theme was created in literally five weeks; the studio worked directly with Erik Bitter who was mentored by Dave Holls, our boss. It was a little bit like the fox in the henhouse. Erik had a vision, and we helped him achieve it.

Special recognition has to be given to Dave Holls who led the design effort, and who knew when we had arrived at the proper design solution. The design was very much inspired by the then current Italian superstar cars, at that time still very much in focus, the Maserati Ghibli and the DeTomaso Mangusta which were both designed by Giorgetto Giugiaro.

Dave convinced Eric Bitter that he needed a car that had Italian character but still unique and distinctive enough to call his own.  Erik brought in some small sketches from time to time to explain his point of view and clearly Dave was open to his suggestions. Dave very skillfully managed the design direction and the creative effort that resulted in a very high quality and classic design, the Bitter CD.

The car is clearly very ‘Italianesque’ of the time, some people have said it may have been designed at Ghia or Bertone, but not so. It was completely a product of Opel Design under the direction of Dave Holls with the strong support, influence, and plain old hard work of Erik Bitter who agreed to combine German engineering with Italian design character.


Dick Ruzzin’s memories of designing the Bitter CD and the others who worked on its creation in November, 1971

In the spring of 1971 I was working at GM Design Staff and had received an assignment by Bill Mitchell to work at Opel Design for six months. After working there for four months, Dave Holls, the Opel Design Director, assigned me to the Opel Design Interior Studio saying that I might not have another chance in my career to work on interiors. With five weeks to go, my six months stay was coming to an end, I was again moved, this time to Herb Kilmers Diplomat Studio to work with Hideo Kodama, a designer from Japan, and another German designer, Brinkmann.

A few weeks before I left to return to the States, the Diplomat Studio received the assignment to do a special coupe design for Eric Bitter to be built on the Diplomat sedan platform. This was an exciting design opportunity, as Erich Bitter had a reputation as a terrific driver, and had made a strong connection with Bob Lutz, who was then Opel Sales Manager for Germany. The Diplomat platform had a fairly low cowl, independent rear suspension, vented disc brakes all around, and something new for Europe, a 225 HP Chevrolet small block. All of that would be carried over to the new two door coupe that would ultimately be called the Bitter CD. For Opel, having the Diplomat platform underpinning in an exotic Italian looking coupe would boost sales interest, they hoped, in the Diplomat sedan.

I already had a sketch up in the studio that Dave liked, a design of an Oldsmobile version of the Vega with a beltline that rose into the rear quarter. We had modeled the Oldsmobile full-size in the Overseas Studio back in the States before I had left for Opel Design, but the project was eventually cancelled.

We immediately started a scale model, and one day when I was working on the body-side, Dave came by and said, “Why don’t you do it like the Mangusta? (Mid body break line, exaggerated wheel flares, and rising line in the rear quarter). I hesitated to do that as I had purchased a Mangusta about a year earlier from GM Design and felt a little strange about using it as an influence on what I was doing. At that time the European design culture was still enamored with two cars designed in the late sixties by Georgetto Giugiaro, the Maserati Ghibli and the DeTomaso Mangusta, which I was very familiar with.


Added 4/30/2015:

At that point in time I was laying out the shoulder on the body side to eventually make it look like the sketch. We would start with a controlled hard line in the clay and then we would gradually roll the hard line off resulting in a soft coning shoulder that started hard at the front, and become increasingly softer toward the rear of the car. Dave saw the hard line before it was rolled off. That triggered his question. We then did not have to roll it off—it stayed as a sharp break and that led to the Mangusta-like wheel flares that were less exaggerated.


I took Dave’s suggestion and we continued developing the scale model of the car that would become the Opel Bitter CD. Actually the CD was strongly influenced by the profile of the Ghibli and the body side theme and surfaces of the Mangusta, even though it had four passenger seating. The quarter window rising at the belt was original but in harmony with the Mangusta’s rising belt line quarter extension, only in glass. The Ghibli influence was known as it was also a factor in the Astra CD, the earlier Frankfort show car. However, no one has known of the Mangustas influence until this account.

The scale model had a long door and a special side window blow-out mechanism to prevent the large side-glass from tipping out at high speeds when there is high air pressure in the cabin. The studio engineer, Herr Plotnikov, worked directly with the studio designers, Opel Advanced Engineering, and Erik Bitter. The Mangusta interpretation was working quite well, and one day when I was drawing cut lines on the scale model, Dave Holls came in and suggested the large glass rear hatch with no exterior framework. This was very unique for the time. George Gallion, Dave’s assistant also participated in the cars design development.

I was to leave Opel Design at the end of November of 1971 to return to my home and work in the United States, but Dave asked me to stay a week longer to finalize the design. My wife was not happy about that. The scale model theme was established and the design was finished except for details on the front bumper and tailamps. George Gallion had originally suggested rounds from the Opel GT which worked very well, but Eric was afraid that they would tag the car as too low in price. Hideo Kodama had also been working on the design and he continued the development, I assume, and completed the project.


Dick Ruzzin’s Opel Bitter

Erich Bitter has built a number of special high performance vehicles in Germany. The design for this car was done at Opel Design in the late fall of 1971. The Baur body is built on an Opel Diplomat platform with Chevrolet engine, automatic transmission, independent rear suspension, and power vented disc brakes all around. Standard equipment included power steering, air conditioning, and power windows. The original Chevrolet small block engine has recently been replaced with a Corvette 350/355hp unit with aluminum heads and roller cam. New exhaust headers and exhaust system also replaced the original, and there are 74,000 kilometers on the car.

Built in Germany at Baur in 1979, the car is #364 of 395 made. There are six of these cars in the USA. It has special paint that is a dark amethyst pearl with a dark blue leather interior. The car spent a short time in Germany and Florida, then was shipped to California and purchased in May of 2013, and driven here to Michigan by my wife and I.


There are accounts that the design was an extension of a previous Opel show car that previewed at Frankfurt a couple of years earlier It was called the CD also and there was a running version or two built by Frua of Turin. That is not the case. Dave Holls saw no future in pursuing the show car design any further and made a critical decision to move to a totally new design direction. One day while reviewing the early scale models he convinced Erik that a new direction was needed, one that blended Italian Style with Opels known engineering value. The large glass hatch without exterior framing on the earlier concept Astra CD is however a carryover of that first CD design.

At home I forgot about the Bitter CD scale model design as I was very busy with new assignments. About two years later someone came into my studio and told me about a great looking Opel in the Design Executive Garage. When I got there I walked around the wash bay and there it was in full side view. I was shocked, it was the scale model…as a full-size running car!

Later I had a chance to drive the car. It was about the size of a Camaro, and felt big to me as I was a long time fan of small cars. It did look very good as the interpretation to full-size was very well done by Hideo and Herb. Of course I am sure that Dave and George were involved as well.

I think that in retrospect it is the best looking of the Bitter cars, designed by very talented and skillful people. Since it is powered by the Chevrolet small block engine makes it very special to me.

I would really like to get one. (And I have)!


Who was Dave Holls?

Dave was hired into the GM Styling Staff after graduating from Michigan State University in the mid fifties. He had only worked a short time in Cadillac Studio, participating in creating the huge fins on the 1959 model, when he was drafted into the U.S. Army and sent to Germany to aid in the U.S. post war effort to restore Europe. He bought a used VW Beetle and spent as much time as possible touring Europe going from one U.S. base to the other for gas at American prices.

Dave was an American hot rodder at heart, a closet people person before it became the thing to do, and a genuine and highly respected classic car authority. He also was a very good designer, and became the youngest studio head when he was promoted to head Buick. Dave had an excellent feel for classic elegance as well as sportiness in automobile design. He moved up rapidly at Design. From Buick, he was promoted to be the Super Chief of the three Chevrolet Studios. He was then assigned to be the Director of Opel Design in Germany, following Chuck Jordan who returned to the States. It was at Opel that he met Eric Bitter who wanted to build a special coupe off of the Chevrolet powered Diplomat chassis. Bob Lutz, who was Marketing Director for Germany, helped push the project forward, mentored the Bitter CD, and was enthusiastic about the design.

Dave returned to the States after three years and participated in the design of many outstanding vehicles such as the 1966 Buick Riviera. A collector of iconic classic cars, he wrote one of the only auto design history books of the time with Michael Lamm, A Century Of American Style. This wonderful book is a benchmark for automobile design history. Dave also was writing a book about automotive aerodynamics, but it was never completed.


Who were Herb Kilmer, Hideo Kodama, and George Gallion?

Herb Kilmer was a German designer hired by Clair Macichan shortly after he arrived in Germany from GM Styling to create a styling staff for Opel.  Herb was a sensitive person and very German with elegant good taste. He embodied everything necessary to design cars that truly required German character and harmony. The Bitter CD was done in his studio under his responsibility.

Hideo Kodama was a designer from Japan, the first hired by a European car company. Hideo exerted a very creative, artistic, and harmonic influence at Opel Design through his beautiful sketches and his personal presence. He also was a very large design contributor throughout the years, ascending to a position beyond Studio Chief. He fathered the Opel Corsa and all of it’s variations for many years. Hideo became a design super star in Japan through his work at Opel and magazine articles about design and illustration.

George Gallion was an American designer from Georgia. He had been assigned to Opel Design as Assistant to the Director in the late ’60s for Chuck Jordan, and stayed for the rest of his career contributing very much to the success of Opel for many years. A bright and very creative person, he was the heart of Opel Design for many years and made many significant contributions to Opel’s success. Before going to Opel Design, his creativity was well known. Working for Dave Holls, he participated in the design of the 1966 Buick Riviera and the 1969 Chevrolet Camaro, two GM Design icons.

It was my pleasure and great good fortune to work with these great designers, all were great car enthusiasts, very skillful and highly motivated, most importantly they were all very nice people. They also became my friends.


Who was Erik Bitter?

Eric Bitter was a German engineer who had started his career as a bike racer and then a very successful race driver. At one time he had worked with Ferdinand Piesche, later to become chairman at VW. Eric started an aftermarket auto accessory company after retiring from racing as a driver and  this led to other opportunities. He quickly decided he wanted to build cars.

He approached Opel through Bob Lutz with the idea to build a special coupe off of the Opel Diplomat sedan which was powered by a 327ci Chevrolet small block V8 engine. During early testing for the Diplomat, Opel had to fit these engines with special marine heads to allow more coolant flow as sustained high speeds on the Autobahn caused overheating. Bitters proposal resulted in the Opel Bitter CD; Herb Kilmer later told me that the name CD was a reference to “low aerodynamic drag,” although the Coupe-Diplomat name is also a logical German interpretation. Bitter, through his enthusiasm and vision, went on to develop a number of special cars throughout the years. The Bitter CD of which 395 were built exists because of Erik’s enthusiasm, dedication and hard work. He is very much admired by all who know him.

Many thanks to Dick Ruzzin for permission to publish these accounts.

  1. ciaran j payne

    What a great and informative article opening up a window on a car I had known about for many years but never knew the GM connection nor the very well known people connected with the development, or indeed, their contribution to European product development influences. More please!

  2. Paul Aitchison

    A very interesting article indeed.
    The Maserati Ghibli influence is undeniable. The Bitter CD is a extremely beautiful vehicle. I only wish more of these were seen this side of the pond.

    I get the feeling several of this iconic people are no longer with us, is this a correct assumption?

    Dave Holls book on aerodynamics would have been of great interest to many, including myself, is there any chance it could be completed and published?

  3. Ken Pickering

    Dave Holls was a good friend and collogue at GM Design. He was a walking encyclopedia on classic cars. I remember the morning that Ed Rollert, newly appointed General Manager of Buick Division, asked me to take him down to the Buick Studio and introduce him to Dave Holls. After a few pleasantries, Rollert reached into his pocket and said to Dave, “I was thinking on the way down from Flint and have these ideas for a Buick front end design”. With out missing a beat, Dave put his arms around Rollert’s shoulder and said, “Ed, you just keep building and selling all those Buicks and we’ll will take care of the design”. End of conversation.

  4. John M. Mellberg

    Thanks for sharing your beautifully written brief about the equally beautiful Opel Bitter CD. It would be great if other fellow members of the Automotive Designers
    Guild and The League of Retired Automotive Designers would make such fine presentations as yours. Perhaps you’ve provided the inspiration to other Designers to come forth to share their own experiences/presentations. I hope so.
    Congratulations on a job well done!
    Best regards,
    John M. Mellberg


    All of Daves writings about aerodynamics are probably at the the Detroit Library Automotive History Section. When he told me in 1971 that he was writing about aero I was surprised as I knew that Dave had very little personal aero experience. I was confused, later I realized that it must have been about how aircraft characteristics influenced cars in history.

    It would have been a good book that would have filled that space before contemporary aerodynamic science which is now well known and understood.
    In the early days of the envelope body “aero was more black art than science” (Kent Kelly).

    Dick Ruzzin

  6. Peter Brock

    Dick …Thanks so much for that beautifully written story on the Opel Bitter. There were so many great designers that passed through Opel….the cars from that period were so elegant. When working at the Tech Center in the 50s I always wondered why GM didn’t transfer some of that great Opel influence to Warren! Dave Holls was one of the best designers I ever got to know at GM. He should have been made the head of Design!. With all your insight and experience i hope you are working on a book. Best, Peter Brock

  7. Scott Ross

    Dave Holls was a neighbor of ours in Bloomfield Township, MI during the early ’60s, and he became a good friend of our family then. We got Christmas cards from him for many years after our family moved away from Michigan.

    Also living nearby then were DIck Baird, the former DeSoto Exterior Styling Studio chief, and Gerry Thorley, who was later the head of Plymouth’s exterior studio. (My brother and I were school classmates with Gerry’s sons.)

    Scott Ross
    Associate Editor
    Super Chevy/VETTE


    I asked Gary to put the two recently image and text up to be part of the story, I recently remembered the sequence of events while making the line drawing that shows the design evolution of the original sketch to the production car. I had kept the sketch but had forgotten the reason why since it was done about forty-six years ago.

    A party was held in Russelsheim at the restaurant where Erik and Dave would go to lunch after his visits to design during the development of the car. I was told the party was going to be put on by the owner for Erik Bitter in memory of the car. I offered to send a copy of the Deans Garage story as it was already up on the site. Suddenly it dawned on me that one of the sketches that I had saved was the CD sketch so I made the design development sketch to match it and sent all of it to Germany.

    Later I was examining it, thinking about the modeling process and how the design would have been evolved. Doing a soft shoulder on a body side was something we all did often and suddenly I remembered Daves intervention. He stopped the process and that is where the hard line came from.

    Dave Holls was a master of so many of the different influences that impacted design, how it was done and all of the people involved who did it.


  9. Pete Engel

    Mr. Ruzzin,
    Thanks for the very in-depth article on a lessor-known but fine “hybrid” Euro-American auto, the Bitter CD.
    It is one of my favorite cars, and on my “bucket list” to own some day.
    The combination of beautiful design, fine coachbuilding by Baur, and American V8, is hard to beat.
    I have never seen one in person. I understand you have shown your car at the Woodward Dream Cruise and elsewhere in the past. I will be attending the Cruise this year (2015) for the first time, and would like to know if you have any plans to display it this year. Please let me know if and where – would love to see it.
    With best regards,
    Pete Engel
    White Post, Virginia

  10. Bladecutter

    Mr. ruzzin, Wonderful article…i know the bitter and vaguely remember, but not a car that i’m much familiar with…the color is extraordinary, first thing to draw my eye, since i’m a straightener refinisher i suppose…looks black light to me, soft, sensual, and understated…the Ghibli is fairly prominent, the Goose influence is much more subtle ..i sense it in rearward rake of roofline, so gentle, w/ the large glass throwing back for both Goose & Maserati. But the elegance as w/ Guigiaro designs is in simplicity of gentle compounds and not busy with chisels and hard angles…my feeling always is, less is more ultimately. This is a lovely automobile, Thanks to You i have come to know and understand it and the People involved, better….over 300hp it must use up pavement at a good rate.

    i saw above a comment to You from one of my Hero’s, Peter Brock….If Mr Brock happens to gloss over this passage, You are high on my list of Admired Mr. Brock…Cobra Coupe’ very high on my list….no wind tunnel? Pure instinct….that Rocks!…..
    .Great read Mr. Ruzzin and an extremely warm and inviting pose, the Bitter………#1 pose for me is still & always will be the Mangusta. jimi buff-it

  11. Tom Semple

    The Astro Gt rear three-quarter shot is made even more beautiful by including a photo of the great George Gallion. Sadly, most show cars are eventually destroyed, I hope this one was not. It is a gorgeous example of a car done under Charley Jordan’s influence. I can almost hear him talking about its “Thin shell.”

    Regards Gary,
    Tom Semple


    Thanks Tom,

    I hope you are doing well.

    Dick Ruzzin

  13. Sheldon Payne

    A beautiful car and interesting story…very well written. I liked all the personnel info too. (Hans Plotnikov, wasn’t it?)

  14. Thanks everyone for the great comments, they are much appreciated I assure you.

    About a year ago on a nice sunny afternoon in the fall I was giving the Bitter CD’s interior its annual leather maintenance treatment when it suddenly dawned on me that the interior door design was like the Mangusta’s, sitting twenty feet away. The passages opened in my memory and I remembered being in the Opel Design Interior Studio where no-one spoke English. I was working on the future Diplomat that sadly would not be produced.

    I made the interior door handles and arm rests like the Mangusta. Then, looking at the tachometer and speedometer I saw the small Opel emblems. The Mangusta had the De Tomaso emblems there also. I do not know if past Opels had emblems there but do not recall that any of those that I drove during my six months there had them.

    Thinking of the design process at hand when the exterior theme was developed the interior them would immediately follow as an urgent need. I am sure that Dave would want to complete the project and move on to other things. George and Dave probably looked around and there it was to be used, my interior full-size seating buck and sketches.

    Those were details and the Opel interior designers did a wonderful job in creating a classic interior design for four people that reflected the exterior, simple, sporty and elegant.

    I can see the car with two contemporary German couples blasting down the Autobahn on the way to Munich for Octoberfest, playing country western music from the Armed Forces News radio station!

    When I left Opel Design, my last day, I met Dave Holls in his office. I thanked him for all the great experiences and the time there. We discussed the Bitter Cd briefly and then he said something that I did not understand at the time. “I want you to identify with the Bitter” he said. I did not know what that meant but I would hear the same words from my next boss within a few weeks as I was given a new assignment, as the only designer, to develop a proposal that I had made. That was the TASC4GT, a rear engine rotary powered Camaro coupe.

    Dave was trying to tell me that I had to go beyond just designing a car, but to think of it completely, every aspect of it, to coordinate and evolve the design with a harmonious aesthetic character. It takes a mature designer to first do enough work to find himself, there are very few car designers who ever have the experience and opportunity to do that.
    I was blessed, more than once.


  15. Sheldon Payne

    While working for Otto Soeding in Adv Vehicle Studio during the mid-Seventies, I became a fan of Opel design, and owned two Ascona wagons. They made great family cars, especially given my daily commute from Lake Orion. Later when working for Nissan, I attended the Frankfurt auto show and attempted to rent an Opel Senator, only to learn upon arrival that there were none in the rental fleet. (This after being assured that I could do it when making arrangements prior to my departure.) In any case, to me the Bitter was the ultimate example of Opel Design at that time.

  16. Tony+Miller

    Great looking car with extraordinary long, lean proportions. I would happily drive one of these.

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