a film about a truck chasing a car?

[sarwal]

is there a film maybe called dunes about a big truck chasing a motorist through the desert? its an old film.... 

[surreyman]

The film you are thinking about is probably Duel an early Steven Spielberg film starring Dennid Weaver. 

[KebabMeister]

http://www.imdb.com/title/tt0067023/

[seal!]

It is deffinatly Duel, and its Steven Spielberg's first film.

[RogK]

I think he was still a student when he made it. It's a great movie. See it if you can.

[littleoldme]

Cracking film. An early example of extreme road rage. Far more terrifying IMO than anything involving demons, vampires or suchlike.