Auto Union was formed in 1932 as a merger between Audi, Horch, DKW, and Wanderer marques – all of which had been firmly established since early on in the 20th century. The four rings signify the four brands. Wanderer was discontinued after factories were destroyed during WWII, the last Horch was produced in 1953, and VW discontinued DKW after purchasing Audi in 1965. From 1965 forward, the four-ring logo has been associated with Audi alone. (Photo credit: S. Connor)