DKW 3=6 Type F 93 Sonderklasse coupé, 1957
In the autumn of 1955, Auto Union GmbH presented its successful model, the 3=6 Sonderklasse, with a 10 cm wider body at the International Motor Show in Frankfurt. The equation 3=6 was coined for maximum advertising effect, a reference to the 3-cylinder 2-stroke engine with performance characteristics comparable to a 6-cylinder 4-stroke engine. In September 1957, the final version of the 3=6 was launched. Most prominent distinguishing feature were the doors, which were hinged at the front for reasons of occupant protection.