Finally! I found this film.
I saw this film years ago when I was a kid and it stayed with me for a long time. I had been trying to figure out what it was, describing it to friends and doing endless google searches. And now I've finally found it. But just to be sure - does this film have a scene where a guy is driving a truck, then it breaks down. When he opens the hood he sees it doesn't have an engine?
"I saw the best minds of my generation destroyed by madness"