The Ghia-built Diablo started out as the Chrysler Dart of 1956. This was an experiment in aerodynamics and featured a fully retractable metal hardtop that slid into the trunk beneath the rear window, altering the line of the rear deck. Designed in the Advance Styling Studio and overseen by legendary designer Virgil M. Exner, the Dart was inspired by engineers watching ink blots moving in 200mph winds along the surface of plastic models. The end result was this almost perfect dart shape, reinforcing Exner's belief that fins worked.

When it was shown to the public Chrysler called it a "Hydroplane on wheels". Painted in silver and black, when testing on the 4-passenger Dart was completed at Chrysler's Chelsea Proving Grounds, it was returned to Ghia in early 1957. Ghia replaced the retracting hardtop for a more conventional soft-top, re-worked the incredible fins and painted it red. The car was then renamed the Chrysler Diablo and sent back to America. The Diablo was powered by a Chrysler 392ci, 375bhp V8 taken from the 300 series. The Diablo stretched to 223inches long, 80inches wide and 54inches high including the fins. The car is now part of the Joe Bortz collection, located in Highland Park, Ill. The Diablo name re-emerged when Chrysler owned Lamborghini launched the successor to the Countach in 1990.