1974 was the last year the Sonett III was manufactured. To help adapt the car to U.S. market tastes, the Sonett III featured a floor-mounted shifter (instead of the Sonett V4 column-mounted shifter) and optional dealer-installed air conditioning. Like the Opel GT, the Sonett III’s hidden headlamps were operated manually using a lever. US safety regulations required new bumpers after 1972, significantly detracting from its Italian-inspired design. The model years 1971 to 1974 of the Sonett III used the 1700 cc Ford V4, but to meet increasingly strict Federal regulations, net power output remained the same as the 1500 cc engine.