Car Wars is a classic paper-and-pencil (and dice) game from the fertile mind of Steve Jackson. The premise is, in the near future, there are food riots, energy crises, limited nuclear exchange, and the secession of Texas, Louisiana, and Arkansas. The most popular form of televised entertainment is a form of demolition derby, with the important distinction of actually using weapons. Outside of autoduels for television, the general lawlessness results in the increase of vigilantes. The cool thing is, the vigilantes have fast cars with armor and neat weapons. Machine Guns, Recoilless Rifles, Rocket Launchers, Flame Throwers, Land Mines, Lasers, Oil Droppers, Flaming Oil Droppers, and Heavy-duty Flaming Oil Droppers are just some of the neat weapons.
The gaming system deals with the car-combat rules. There's a strong element of RPG due to the interesting setting, and the GURPS system has a sourcebook for Car Wars based campaigns. The rulebooks are interesting just for the backstory and general humor.
Car Wars inspired the old computer game Autoduel, which is the grand-daddy of Interstate '76 and its sequels.