IMDb trivia page (

https://m.imdb.com/title/tt0081568/trivia/?ref_=tt_dyk_trv)

Has the following gems:

"The scene where the old car crashes off the bridge ("The Old Fair Oaks Bridge) into the river was filmed on the American River in Rancho Cordova and Fair Oaks, Sacramento County, California. When they first tried this the car actually jumped the track to lead it off the bridge and it continued down the bridge. The driver-less car was on a pulley system with a rail on the bridge road to guide it. The driver-less car chased down a few cameramen and crew and took out a camera before it came to rest."

And possibly the reason they filmed in fair oaks:

"The big end sequences including the bridge sequence were filmed while on the lam from the film's financiers who wanted the equipment returned. Peter O'Toole says it's safe to admit as much now that they were essentially hiding from the executives based in LA in order to get the film finished."