Director Sam Peckinpah allowed actor and long-time associate James Coburn to work on the movie as a second-unit director to get his DGA card. Rumor has it that Coburn actually directed some scenes when Peckinpah was "unwell."
The film was a hit in the Soviet Union, showing a working-class rebellion against a corrupt government.
Whilst the film was a hit, Sam Peckinpah's behavior onset made him uninsurable. It would be five years before he directed another film.
Although the movie was inspired by the 1976 song of the same name, the song didn't have much of a plot. After the screenplay was written, Bill Fries (aka CW McCall) recorded a new version, with lyrics that incorporated the characters and events of the film. That version plays during the final credits.
Most of the "Jesus freaks" on the micro bus are played by members of Kris Kristofferson's touring band from the 1970s.