The DKW 3=6 is often described as the big DKW. (Der grosse DKW) It claims room for six, with space for luggage -- all powered by a 2-stroke, 3-cylinder, 891cc engine. (A straight three.)
The car, manufactured from 1953 to 1959 went by many names. It was the DKW 3=6, the DKW Sonderklasse, the DKW F91, and the DKW 900.
One would assume the 3=6 is in reference to the 3-cylinder car with seating for six. But, according to the Audi history site, "Three equals six! This simple mathematical equation greatly impressed the public. A three-cylinder two-stroke engine, since it has twice as many working strokes as a four-stroke engine, therefore benefits from a power flow as smooth as a six-cylinder four stroke."