This should be easy. There are tons of great car movies to choose from - Fast and Furious, Death Race, Smokey and the Bandit, Christine. I'm going to go for an obscure, GenX horror flick a la Spielberg's Dual. The name of the movie, fittingly, is simply "The Car." James Brolin starred as a Western sheriff tasked with protecting his community from a possessed, driverless car. Very cool flick.
What's your favorite?