There’s a good thread at Ask Metafilter thread this morning: At what point is a car not worth repairing?

My ten-year-old 130k-mile Saturn is showing its age pretty badly — leaking oil, disturbing noise coming from the front end, crumbling exhaust system. I’m having a tough time coming up with a satisfying way to determine if it makes financial sense to pay for the repairs or to just ditch the car and buy a new one (living carless isn’t an option, cool as it would be).

The discussion includes how to decide when to buy a new car, whether one should buy new or used, and the advantages (or disadvantages) of leasing. One poster invokes the Car Talk guys, who say: “It is always cheaper to keep driving your old car than it is to buy a new car.”