Horch left Audi in 1920 and went to Berlin and took various jobs. He published his autobiography,
I Built Cars () in 1937. He also served on the board of
Auto Union, the successor to Audi Automobilwerke GmbH he had founded. Horch remained an honorary executive at Auto Union during and after its reincorporation in
Ingolstadt,
Bavaria, in the late 1940s until his death in 1951, ultimately not living to see the later resurrection of his Audi brand a decade later under the ownership of
Volkswagen. He was an honorary citizen of Zwickau and had a street named for his Audi cars in both Zwickau and his birthplace Winningen. He was made an honorary professor at
Braunschweig University of Technology. There is an
August Horchstrasse (August Horch Street) at Audi's main manufacturing plant in Ingolstadt. ==References==