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.
- Engine: 3-cylinder, 2-stroke in line
- Displacement: 896 cc
- Power: 40 hp at 4,250 rpm
- Maximum speed: 125 km/h
- Fuel consumption: 9 litres/100 km
- Price: DM 6,475
- Series: 1955-1959
- Production: 157,016 cars