Director Randall Hood died of cancer during post production in 1976. It was long rumored that Clint Eastwood came in to help finish the film as a favor to lead actor Jack Ging.
Hugo Friedhoffer was so upset by the death of director Randall Hood, which happened before the score was recorded, that he never scored another film. This is his last credit.
Shot in 1972. Director-producer Randall Hood then ran into production problems and the completed (but unedited) film languished on the shelf until Hood's death of cancer in 1976. It was the movie's star, Jack Ging, who took over, overseeing post-production to finally bring it to the light six years later, in 1978.
Jack Ging's character drives a 1976 Pontiac Bonneville throughout the film, and several other models (including the police cars and taxi cab at the end) are from the mid-70's, not the early 70's. According to the end credits, vehicles were supplied by Pontiac (although this only seems applicable to Ging's sedan), and the carmaker would've supplied only current or newly-introduced models, meaning this film was shot in 1976 or possibly late 1975 at best, when the 1976 Bonnevilles were available.