Ford Advanced Vehicles built four GT40 roadsters in 1965, two went to Shelby American for race testing; two have been missing for years. Mike Gulett blogs about the rare roadsters at My Car Quest.
It all started with the handcrafted Ford X-1 sports racer, above, top, a lightweight, open-cockpit version of the Mark II GT40. It was run with very limited success in classes for modified sports cars. Ford Advanced Vehicles used the X-1 and subsequent GT40 roadsters to test ZF transaxles, as the GT40s were originally fitted with Coletti units. In 1966, an open-top Ford Mark II sports-prototype, above, based on the X-1, won the Sebring 12-Hour.
For more about the open-cockpit Ford GT40s, please visit http://mycarquest.com/2013/04/two-1965-ford-gt40-roadsters-one-was-lost-and-found.html