Budget Beater

Definition:

A budget beater is a car that you buy for an insanely low amount because the car has many problems, but it still runs, for now. You put absolutely no money into the car and drive it until it dies - hopefully no less than six months.

Exemplification of usage:

Him: Dude, what's up with the car you bought? It's like three different colors. Me: It's all I can afford. I can't afford a car payment, so I'll just drive this budget beater until it dies.