The Shelby Mustang is a high performance variant of the Ford Mustang, built by Ford from 1968 through 1970. The 1965, 1966 and 1967 Shelbys were a series of Ford Mustangs which were specially modified by Carroll Shelby's company and sold under the name Shelby GT with identification badges Shelby Cobra. From 1968 the model became the Shelby Cobra GT. The 1966 was differentiated in body color (non-white versions were introduced — colors included blue, red, green and black, as well as the original white) and trim. The "Le Mans" stripes were continued as an option, as in 1965. It featured special quarter-panel windows and rear air scoops on each side and an optional automatic transmission. A fold-down rear seat was now standard as well. Where early 1965 cars had black engine blocks, 1966 and later cars had the 289 engine painted blue. The first 252 GT-350s for 1966 were "carry-over" cars. They had the 1965 Ford Mustang Bodies and 1965 Ford Mustang serial numbers under their Shelby serial numbers.