According to director Jack Hill, it wasn't until they were actually shooting that he learned that Sid Haig, who plays Hawk, the racing champion, didn't know how to drive a car.

Final film of Brian Donlevy.

The magazine Rick Bowman (Dick Davalos) is reading in the hotel room is the January 1967 issue of Hot Rod. On the cover is a picture Dan Gurney and his Gurney Weslake engine.

For only one moment is there an actual Pit Stop in the movie, and it's not a working Pit Stop with mechanics fervently fixing up a car mid-race: when Sid Haig's Hawk pulls out of the race after his engine is blown, it's in the pit stop: the announcer even refers to it as such.

Although the Pacific Northwest psychedelic band The Daily Flash is credited with the rock music heard on the film's soundtrack, surviving band members claim that they don't actually know which personnel performed that music. It may have been performed by a mix of band regulars and miscellaneous musicians who were hanging out with them.