I keep it until it can't do the job it was built for.
My car: '97 Hyundai Elantra GLS, rebuilt.
It was bought in 2000 for $5k with 35k miles on it. It's still running reasonably well, and approaching 100k miles. About once every two weeks it has a little trouble starting, but it always does get going eventually.
My sister's still got her first car as well.
My mom's car is....I don't know how old. 15 years, possibly more.
My dad tends to keep his cars until a deer wrecks them; he seems to have a knack for hitting them after dark, though once during daylight one smacked into his back passenger door. My car, my sister's car, and my dad's various cars have been bought from a guy, Randy Knecht, who rebuilds them as a business. He generally buys insurance wrecks and then does a damn good job rebuilding and refurbishing them. Some of these things are pretty messed up, too - a few even come in with head imprints on the windshields. :Q (Wear your seatbelts, dammit!)
I have had some things fail on the car over the years. Notable ones:
- One radiator fan died. A replacement was only $30, pulled off another car in his lot.
- At least two of the power window motor assemblies have died, though I don't know the failure mode. But the result is the same:
A nylon pulley is broken in half, and the braided steel wire used to move the window carriage is all screwed up and unusable. So I don't know if the steel wire gets frayed, tangles, and the tension snaps the pulley, or else if the manufacturer cheaped out and used plastic pulleys where metal should really be used. In my experience, it's probably the latter.
One of the motor units got replaced; the other, I just don't have the money for it right now. I made a few modifications such that the leftover steel wire is bolted in place to the door, holding the window closed semi-permanently.
