Interesting question about the 2nd gen Firebird windshield and No. 1 pillar. Hank Haga and I had a contest going to see who would master the upper. Henry was very much under the influence of Giugiaro, his Maserati Ghibli, etc., in other words, the new planar Italian style. I was equally under the influence of the English designers who came out of the British aircraft industry. That included the Lotuses and E Jags. I actually loved the stiff vertical windshield of the E Jag coupe, but was also very taken with the earlier Ferraris that had the faster compound conical glass forms where the header was rather flat but the base of the windshield was very round in plan, necessitating conical surfaces from the upper corners angled inward toward the center of the windshield at the cowl.
Originally the windshield angle of the Camaro/Firebird was considerably faster than the final version. But the extra glass was costly and Pete Estes, Chevrolet General Manager, agreed to reduce the cost (and weight) by moving the centerline rearward at the cowl. I (in Pontiac) was pretty upset by this because it meant that the cowl in plan view became flatter and I was robbed in some degree of the Ferrari-like conical effect which I had achieved some measure of in my version of the upper. But I determined to make the best of it and countered with the idea of a “virtual glass plane” in front of the actual windshield. I explained this in Edson Armi’s original book (The Art of American Car Design, Penn State U Press, 1989) because he raised questions about that upper that are related to yours.
If you sight the centerline profile of the header you will notice that it does not curve downward into the windshield but aims further forward, headed for the earlier, faster, windshield profile. This imaginary virtual profile kind of re-connects, so to speak, with the cowl profile and hence the hood quite a ways forward of the actual windshield glass plane, (not far from the profile of the original faster windshield) allowing space for wiper storage and air inlet grilles for interior HVAC. This imaginary, or virtual windshield if you will, completes the shell of the car but the stiffness of the pillar itself and the way the upper windshield DLO slices across and forms the header provides a hoop, so to speak, from which the rest of the upper unfurls. This is especially true of the outer shoulders of the upper which are also conical, their radii growing larger as they flow back to the sail panels.
Much to my surprise, Irv Rybicki and Jack Humbert—MItchell may have been involved, but I kind of doubt it since he was a line man rather than a form guy—chose my upper over Hank’s, thus the English and older Italian influences won out over Giugiaro’s Italian planar style. That may be why the 2nd gen Firebird is something of an anomaly in the evolution of GM (and most American) cars of the day, the majority of which were moving in the direction of the ’70s mainstream where creases and planes reigned supreme.
Many thanks to Bill Porter for sharing this interesting account.