You wouldn't mind if you were car-jacked. You judge suitable parking spaces by the degree of downhill slope. You have the local tow company on speed-dial. The engine catches fire and you don't notice anything wrong until the firetruck pulls you over. You can leave your car parked, unlocked, with the keys in the ignition, and not worry about it being stolen.
Public transportation starts to look good.
Your entire car isn't worth the minimum insurance deductable. Even homeless people look derisively at your car. Every time you start your car, the local smog index jumps a whole point. The 8-track tape deck finnally eats your last tape.