My heart is always with Tatra, but I'll admit I'm intrigued by the Sachsenring. It was built at the Horch plant which was in East Germany. Horch is one of the four rings in the Audi emblem. Audi, Horch, Wanderer and DKW merged to make Auto Union in 1932. VW bought Auto Union in 1964 and revived the Audi brand to build luxury cars.