Producer Hugh Hefner insisted that Barbara Hershey's $50,000 fee be cut in half when she insisted on being billed as "Barbara Seagull" as the new name reduced her box office clout.
Items found along the freeway were used to decorate Vrooder's cave, such as car parts, crates and other debris and trash.
The police helicopter used in this film is a 1961 Bell 47J Ranger, registration N73202. Its registration was canceled in 1988 and it was sold to a party in Australia where it is registered as VH-NHR, and it was still active as of 2018. This helicopter can also be seen in The Satan Bug (1965), Motorcycle Boogie (1977), The Mouse That Died (1970), and The See-Paris-And-Die Affair (1965).