Nearly six decades ago, American GIs fighting against Hitler's armies in Europe were astonished to discover that the German military drove Ford trucks. If the GIs had looked up to the sky, they would have seen the Nazis flying planes built by Opel, a wholly-owned subsidiary of General Motors. In 1939, the German branches of GM and Ford supplied 70 percent of cars sold on the German market. German subsidiaries of both auto giants went on to manufacture military materiel for the armies of the German fascist state. Archival research has established that some managers in both firms, US citizens, failed to resist the conversion of GM and Ford plants in Germany and German-occupied France and Poland, to German military use.