Mary Woronov didn't know how to drive when she acted in this film, so the van she drives in this movie had to be towed with a rope.
According to Mary Woronov, Paul Bartel did not enjoy making this film because he felt he was being typecast as an action director. Even David Carradine tried explaining to Bartel that he was unsure about the climatic car pile-up and its disturbing subject matter.
David Carradine and Robert Carradine had appeared together previously in Martin Scorsese's 'Mean Streets' (1972) and Gerrit Graham and Archie Hahn had appeared together previously in 'Phantom of the Paradise' (1974).
Wolf Messer, the West German professional racer branded American cars as "stupid" despite the fact the De Tomaso Pantera that he drove is powered by a Ford Cleveland 351 engine and was sold by Ford in the US up until 1975.