On January 12, 1991, in Detroit, Michigan, the North American International Auto Show was held, over nine days. American Sunroof Corporation and Don Runkle, General Motors’ chief of advanced engineering, unveiled the Corvette ZR-1 Spyder, the prototype convertible ZR-1.
GM did not produce a convertible version of the C4 ZR-1 but did make a few prototypes which were drop tops. The black example in the National Corvette Museum was originally painted Sebring Silver with a Neutrino Yellow interior.
After the show, it was repainted black and the interior color was changed to red. The car has many unique features no other C4 ZR-1 has such as custom billet aluminum wheels, a custom tonneau cover with a waterfall, a chopped windshield, narrowed side mirrors and a louvered hood with the signatures of all those involved in building the car written on the underside. So far, the NCM has been unable to find the hood.
The ZR-1 Spyder features unique hood and quarter panel vents to aid in engine compartment cooling. A new tonneau cover flows from the rear deck lid into the passengers compartment, reflective of Corvettes from the late 50’s and early 60’s. Individual aero bars are integrated into the body work behind the seat. The windshield and sideglass have been lowered, accenting the “slingshot” design treatment.
This car was a joint project with General Motors Advanced Engineering Staff (AES) and American Sunroof Corporation (ASC). The vehicle was produced at the CPC Bowling Green plant and the signatures of those involved in the project are on the underside of the hood and rear deck lid.