GM president and Chevy engineering alum Ed Cole instigated round two as a showcase for his pet project: the lightweight, power-dense Wankel rotary engine. R&D got the job first and built a light, agile small sports car around a 180-horse, two-rotor engine. Duntov and Mitchell were unimpressed and responded by hitching two such rotaries together, souping them up to make 420 horsepower, and mounting them to the modified Toronado drivetrain in a recycled XP-882 chassis. The aero-sleek skin penned by Henry Haga, under the direction of Chuck Jordan (and Mitchell), blew the rival 2-Rotor's away and stole the Paris show where the two cars shared a stage. This round was called on account of the OPEC oil embargo that doomed the thirsty Wankel's future.

Round three was almost tooled for production. In 1977, the 4-Rotor show car was dusted off, outfitted with a 400-cubic-inch small-block, and rechristened Aero-vette. Between Bill Mitchell's loud advocacy of this gorgeous mid-motor Vette and perhaps a perceived threat from ex-Chevy boss John DeLorean's own mid-engine DMC 12, GM chairman Thomas Murphy approved the Aero-vette for production as the 1980 Corvette. But Mitchell's retirement that year, combined with then Corvette chief engineer Dave McLellan's lack of enthusiasm for the mid-engine design and copious marketing data about other slow-selling mid-engine cars, killed the last best hope for a mid-engine Vette.