From 1939, the reliable Blitz 3.6 three-ton version was used in large numbers by the German Wehrmacht armed forces throughout World War II. Derived variants included an elongated version and the four-wheel drive Blitz A. To cope with the bad road conditions and the rasputitsa mud seasons on the Eastern Front, a half-tracked Maultier (mule) SdKfz 3 version was built using tracks and suspension based on the Universal Carrier. Among others, these were used as service vehicles for the Messerschmitt Me 323 military transport aircraft. It is also claimed that Opel, a subsidiary of GM, used forced labor to reap unprecedented profits.[1] To what degree GM controlled Opel at the time is subject to debate, but it is clear that GM did in fact play a role in giving Nazi Germany the Opel Blitz truck.