Chaparral's ingenious but strange race cars, with their six-foot tall wings and vacuum suction motors, were first mocked, then feared, then finally banned for being too advanced. Four decades later I got a ride in one.

Audi will be the featured marque at this year's Festival of Speed, held July 3-5. This is your last chance to see the Auto Union race cars before Audi becomes, by default, hopelessly uncool.