Rare Corvettes · One of one

The XP-700

Most concept cars are built to be looked at. Bill Mitchell built this one to be driven — by himself, to work, for a year. And when GM finally put it on a show stand, the tail of it was a spoiler for a production Corvette nobody had seen yet.

GM Styling, Detroit — 1958

In 1958 Bill Mitchell was Vice-President of GM Styling, freshly installed in Harley Earl's old chair, and in the middle of the most productive private hobby in Detroit: building himself cars. He took a stock 1958 Corvette and had the Chevrolet studio rework its fiberglass body into something that looked like a Grand Prix racer had wandered onto a road-car chassis. They called it the XP-700. He painted it red. Then he drove it — as his personal car, for the first year of its life.

The double bubble

In October 1959 the car went back into the studio and came out transformed. The headline was the roof: a double-bubble Plexiglass canopy, a shape Harley Earl had always loved. The obvious problem with sealing a driver under a clear plastic dome is that you have built a terrarium, so the canopy was coated in vaporized aluminum to turn back the sun, and the center pillar between the two bubbles was hollowed out to carry a ventilation system. It is a wonderfully 1959 solution — solve a problem you created, with a metallized roof and ductwork hidden in the spine.

The rest of the rebuild was quieter and mattered more. The grille cavity was reshaped into an ellipse and fed by a new scoop underneath. The side pipes stayed. The tail was lengthened. And the whole car went from red to metallic silver before it was shown to the public in April 1960 in New York.

The spoiler nobody noticed

Here is why the XP-700 matters more than its bubble top suggests. That lengthened tail, and the wraparound bodylines running back from the cockpit, were not styling doodles — they were the 1961 Corvette arriving early. When the '61 appeared with its new ducktail rear, it was showing the public a shape that had already been driving around Detroit under Bill Mitchell. The same rear-end thinking carried on into the second generation.

The XP-700 is the connective tissue of this era: Mitchell's personal car, Earl's taste in roofs, the last of the C1, and the first hints of what came next. He was doing the same thing at the same time with the Stingray Racer — running his own projects, on his own terms, and letting the production Corvette catch up afterward.