Alfa Romeo Disco Volante—the original inspiration for styling of the mid-year Corvette.

Studio X: The Story of Bill Mitchell’s Secret Styling Studio

by Gary Witzenburg. Published in Motor Trend, December 27, 2017.

Bill Mitchell’s secret styling studio sourced some of GM’s greatest cars and concepts

It was a cold November morning in 1957 when William L. “Bill” Mitchell, heir apparent to General Motors’ industry-dominating design team, strode unexpectedly and atypically alone into the automaker’s basement Research B styling studio. Just back from the Turin, Italy, motor show, Mitchell was thinking how great a second-generation Corvette could look if it borrowed some themes he had seen on the streamlined Italian sports cars at the show.

But Mitchell faced a seemingly impenetrable barrier: On June 6 of that year, the all-powerful Automobile Manufacturers Association (AMA) had forbidden American automakers from participating in any performance or motorsports activities—which included the building, selling, or advertising of performance-oriented products.

This ban was a delayed response to the horrific crash at the 1955 24 Hours of Le Mans, which had killed 77 people and injured as many more. The strong-willed Mitchell—a brilliant designer and racing and performance enthusiast soon to replace the legendary Harley Earl as GM’s styling chief—was told the AMA prohibition meant Chevrolet’s still-struggling Corvette would be removed from the lineup. Michell wasn’t about to let that happen.

So he decided to do what most anyone in his position (with a bold anti-establishment drive) would do: set up a clandestine studio hidden from the prying eyes of GM executives, accountants, divisional managers, and anyone else not directly involved—even other designers and studio chiefs.

The result: Some of GM’s greatest cars and concepts—including the spectacular ’59 Stingray Racer, which previewed that next-gen Corvette, hot Monza GT and SS concepts, swoopy Astro I, Astro II, and aircraft-look Astro III idea cars, two Mako Shark concepts, and a Mini-Camaro small-car project—would be created in secret over the next decade.

But those cars were still to come. In 1957, significant world events were afoot. The baby boom was in full swing, the average income was $4,550, the average new house cost $12,220, the average rocket-finned car sold for $2,749, and a gallon of gas was 24 cents. Dick Clark’s American Bandstand teen-dance TV show made its debut, and Elvis’ “Jailhouse Rock” was such a hit that he bought a Memphis mansion and called it Graceland.

With America in confident ascent, Mitchell believed that the racing ban wouldn’t last very long. He wanted a new Corvette design ready. And he needed some trustworthy designers who wouldn’t attract much attention to do it. Knowing that it would take some time to set up and equip the secret studio he had in mind, he decided to kick off this special project in his basement Research B studio, where few if any other designers or executives would notice.

Research B was leanly staffed, with only three or four young stylists present when Mitchell walked in that chilly morning. Peter Brock (the same person who would years later design Carroll Shelby’s Le Mans–winning Cobra GT) recalled what happened: “He sat down and told us what he wanted to do. And we were looking at each other thinking, ‘Is this for real? He wants to give us the Corvette program?’

“He pulled out a bunch of pictures from Turin and laid them out, and they all had a crisp line around the belt separating upper from lower and aerodynamic shapes over the wheels. And the one that really got to him, even though it was two years old by then, was the Alfa Romeo Disco Volante. Alfa had done roadster and coupe versions, and Mitchell wanted to do the first Corvette coupe. He said, ‘OK, guys, give me your best. Put it up on the walls. I’ll be back in a few days to check it out.’”

Brock’s theme ultimately won that competition, and with Mitchell stopping by and coaching every few days, his youthful team (also including Gene Garfinkle, Chuck Pohlman, and Norm Neumann, under studio head Bob Veryzer) took it from sketches to a one-fifth-scale model and then to a full-size clay model.

But as the AMA ban lingered, Mitchell decided to evolve that radical concept design into a prototype racer that he would own and campaign himself out of his own pocket, a bold move to test it publicly with no clear connection to Chevrolet or General Motors.

He told the designers to lose the model’s roof and make it a roadster. With designers and modelers working at breakneck speed, the concept was moved, in the dark of night during the 1957 Christmas break, to a secret studio Mitchell had quickly built behind a tool room called the Hammer Room.

“He put in a false wall,” Brock said. “And only he and the guys working there were allowed to go into that secret studio in back. Walking down the hall, looking into the Hammer Room, it looked like a regular tool room.”

The File Room

It was there where this striking model (now designated XP-87) was further developed by ace designer Larry Shinoda and “board man” Tony Lapine into the jaw-dropping 1959 Stingray Racer. And shortly after Mitchell replaced Earl as GM Styling vice president in December 1958, he called staff assistant Ken Pickering into his office and asked him to find a more suitable space to do special projects in ultra secrecy. Pickering walked the entire studio building, but he found no available space. Then, looking at a blueprint, Pickering found a vacant basement room across from the administration building elevator. It had been Earl’s personal file room.

“It was a small room with just one door, but with modifications it could become a working studio,” Pickering said. “[Mitchell] loved the location, as he could have close and direct access from his office—just a short walk to the elevator and down three floors—so he directed me to make it into a studio. We removed walls and replaced them with movable panels, upgraded the lighting, and moved in a modeling platform and other studio equipment, and Mitchell had his secret Studio X.”

A windowless space, it could barely accommodate a small design team and the model they were working on. “By my recollection, the studio was approximately 40 by 15 feet with room for one platform for a car and two drawing tables, a small table for the coffee pot and an even smaller table for the telephone,” said designer Roy Lonberger, who headed Studio X from 1965 to 1968 and years later authored the definitive book, Maestro: Bill Mitchell and the Iconic Cars of GM Styling.

“Adjacent to the platform was the drafting wall, where the full-size lofting drawing was created and sometimes used to pin sketches,” Lonberger said. “The opposite wall, also a sketch-display wall, consisted of folding doors that had to be opened whenever a model was removed. The ceiling was low, maybe 7 or 8 feet. Nothing glamorous, very claustrophobic, and a rather depressing place to work.”

Mitchell once said that “designing in Studio X is like trying to play trombone in a phone booth,” according to designer Jim Shook, who worked there on an advanced Oldsmobile Toronado concept in the 1960s. Nonetheless, XP-87 was moved into Studio X (again, at night) and finished early in 1959.

Its public debut came April 18, 1959, at a race in Marlboro, Maryland, carrying no badging except “Stingray” in chrome script on its sides. Piloted by Dick Thompson, it went on to win the 1959 and 1960 SCCA class championships. Then Mitchell drove it on the road, and its stunning design soon evolved into the ’63 production Corvette Sting Ray.

Ideas and concepts

Mitchell had several scattered secret studios during that decade, and the records of some were assigned to other programs to hide their costs (and existence) from corporate accountants.

Secret racing cars and some other Mitchell pet projects were designed in the Warehouse Studio (across 12-Mile Road from GM’s Technical Center), in Chevy R&D’s “skunkworks,” and at Jim Hall’s Rattlesnake Raceway in Midland, Texas, so Mitchell could truthfully say that they were not being done at GM Styling.

Studio X churned out performance concepts until 1967. But when Chevrolet/GMC Group chief designer Irv Rybicki was promoted to executive in charge of Styling, he closed Studio X and its satellite studios in an effort to change GM Styling’s focus, “forever ending the Mitchell passion and design essence of Studio X,” Lonberger lamented.

Mitchell reopened Studio X a decade later for one final project, a special one-off car he wanted as his own retirement gift, and he assigned designer Bill Davis to create it.

“It needed to capture his design philosophy of excitement, originality, power, elegance, extreme proportion, flowing lines, shear surfaces, and innovative features,” Lonberger wrote in his book. That challenge was well met by Davis in creating the Pontiac Phantom. Pontiac supported building a running car on ’67 Grand Prix mechanicals but later backed out. Then Howard Kehrl, Mitchell’s GM Technical Staffs boss, killed it. It came close to destruction but received a last-minute reprieve and lives today in the Sloan Museum.


Intrigued by the lore of Studio X, Ed Welburn—GM’s design vice president from 2003 through his 2016 retirement—established his own secret studio to develop the 2006 Camaro concept car.

“I don’t know how anyone could work in that small space,” Welburn said of the original Studio X. “I knew there were special projects being done somewhere in the basement, but I never tried to find it. It was always off limits. I didn’t even know where it was when I worked for Mitchell.”

Still, Welburn decided he needed such a place “to do some very private work,” he said.

Other projects done in Welburn’s Studio X included a 2009 Stingray concept car (which later starred in a Transformers movie), some very early C7 Corvette work, and “The Beast,” the latest presidential limousine.

“I used it very much the way Mitchell did,” he said. “No one knew where it was or what we were doing there.”

One day Welburn took his boss, product development vice chairman Bob Lutz, to the modern-day Studio X to see the Camaro concept. “I took him on a very indirect route—downstairs, upstairs, and downstairs again—to keep the location secret,” he said. “When we got close, he saw a photograph on the wall and commented on it. I told the guys to get rid of it because it would tip him off to where we were. But he said there was no way he could find his way back.”

Lutz recalled seeing that secret Camaro and the influence it had on the eventual production model. “Yes, I saw the ‘parallel’ Camaro that ultimately became the concept car,” he said. “The ‘official’ one was not going well. It looked like a boxy version of the ’67. The ‘secret’ one became production, adapted from the concept. I knew Ed had a studio which he used for clandestine projects but didn’t worry about it because I knew he’d always bring me into the loop at the right time.”

When Welburn retired, the secret studio was dormant. He said he doesn’t know whether Michael Simcoe, his successor as GM Design vice president, is using such a secret space. So we asked him.

“Yes, secret places still exist here,” Simcoe said. “Vision projects have their own energy and need their own space and time to grow. Some ideas may stay secret while others will have a real impact. After all, it’s Design’s role to push and provide a vision to the company.”

Good to hear. We can’t wait to see whatever wild and wonderful designs emerge.


About the gallery: I went through my archives and found a few photos that were probably from Studio X. Source: Roy Lonberger and General Motors.

  1. Very cool. More cars need to be developed this way, rather than relying on CAD and Focus Groups. If the Original ‘Vette was subjected to focus group scrutiny, it would’ve never even happened. All car companies need visionaries, with passion and unbridled talent and energy to survive. I know the bread and butter cars pay the bills, but you need the “halo” cars to bring them into the showroom. More Vegas were sold when there was a Corvette next to them, than a tan 4 door post Chevelle. It’s human nature. People are drawn by the flash and dash , come back down to reality and leave the lot with the practical car, dreaming about the other all the way home.

  2. Peter Robinson

    Yes, it’s certainly Battista PF sitting next to Bill Mitchell. No doubt.

  3. Tom Semple

    Ed Welburn never knew about Studio X, or where it was? Just vague rumors? It had a big sign saying “Studio X” on the door. Everybody knew where it was—down by the print room next to the candy machine. Good designers worked there, many escorted by force, some weeping openly. Most regarded being assigned there as being sent in shackles to some dark region described by Mr. Dante. Myths are great to see develop over the course of ones lifetime, especially something that further enhances “Styling Mystique.”

  4. Norman

    Yes, definitely Signore Farina, though I wanted Taruffi involved.

    Is it possible in today’s world to really tell Bill Mitchell’s story? Those of us who knew of him thought of him as a combination of any number of famous designers all in one.

    But the Byzantine nature of General Motors meant that even he had limits inside which he had to work. That said, Mitchell makes the Don Drapers of that world look like pretty small.

    But can anyone tell me which other GM Dream Cars he street drove? I know he drove the drool worthy Sting Ray and Manta Ray. Which others? Corvair GT, perhaps?


    Norman: WLM often drove many/all of his creations on the street. The Buck Silver Arrow was his most often used driver. The most outlandish was the Scarab F-1.

    Tom: With respect, I think that you are talking about the basement studio where the AeroVette (4rotor) was born. It was near the print room and fab shop. But it was not Studio-X. It was Chevy-3 under Hank Haga. Studio-X was next to the executive elevator, never had any names on the doors, and in fact never had doors (only side walls that opened). Rybicki closed Studio-X in October 1967 when he took charge of Styling. Mitchell reopened it for one last hurrah in 1977 to build the Madam-X/Phantom as his retirement car.

  6. George

    Investor’s Business Daily had a good article on Earl Harley this week (october 20th, 2018).
    Source for the article was a book with the title of FINS by Knoedel Seder.

    Earl Harley was a great visionary of the automobile industry.

  7. Douglas Raap

    I’m a “next generation” transportation clay modeler. Trained by Bob Marianich from GM. Meaning I’ve only been in the industry for the past 33 years. Never in Detroit, Only west coast and Europe. How did the modelers get the clay to shine like that? Shellac? Nice trick to see the highlights before DiNoc. Thanks for the fantastic web site.


  8. Norman Spirit

    Mr. Mitchell street drove that chopped/channeled/extended Riviera? Wow, that must have been psychedelic…

  9. Studio X was across the hall from the elevator that went to the second floor executive offices. Next to it was a stairwell that exited in the hallway between the first floor lobby and the executive garage, as well as going up to the second and third floors. Studio X had a regular entry door on the south side as well as a series of folding doors that opened the entire west wall.

    The TASC4GT was done there by myself; Ray Hildebrand the sculptor. Nate Hall was the studio engineer. The Studio was called Advanced Design 3 and was started in March of 1972. Mitchell allowed Clare MacKichan to use it to create a rotary powered rear engine Camaro. Starting with a very refined and realistic un-cheated 1/3 scale model, the three of us developed the car full-size in four months. We all were re-assigned and left when the model went to the plaster shop to be cast.

    Studio X was very small, and getting the model out was very difficult because it was 187.1 inches long. We took it outside only once to see it, and Bill brought Ed Cole down once when the model was almost ready to be di-noc’d in color (the only time).

    About a year later, 1973, Bill Mitchell started the Four-Fendered-Farkle in Studio X. The car eventually came to the studio that I was heading, Advanced Design 4 (I think). Hank Cramer and Bruce Brooks came with it and we spent about six months on it when he approved it for casting so that a fiberglass model could be made.

    Irv Rybicki became Mitchell’s successor long after that.


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