The sporty version of the Kadett C was introduced in 1975 and was called GT / E. Equipped with a 105hp 4-cylinder engine, the car enjoyed great success and was widely used in competitions, thanks to the Group 1 and 2 homologation. Already in its early career, at the 1976 Monte Carlo Rallye, the GT / E obtained an exceptional fourth place overall with Walter Roehrl. In 1977 the displacement of the GT / E was brought to 1979cc for a power of 115 horses, thanks to the tuning by Irmscher. 8660 units of the GT / E 1.9 were built - and 2234 units of the 2.0.