Anything cheap that runs forever and on the minimum of maintenence is the ideal. We have a '77 Chevy Nova we bought for $750 dollars. We had the brakes fixed when we first got her (last December) and other than regular oil changes, it's all the work we've had to do. She gets 12 mpg, and can carry a guitar, two fiddles, a bodhran, two fat @$$es, and half a sound system.

She does have holes in the floorboard, and we get our feet wet when it rains, but they serve as an excellent alternate brake system.