The supposed metrics are, does it cost more per year than payments? or is the price of the repair more than half the value? (The flaw hidden in that theory is, are you doing the labor? If you wouldn't, and someone else would, the car is still worth having - to them.)

The really irritating thing about cars right now is that the head unit gets obsolete too fast. My 2012 truck really can't quite handle Siri correctly and it predates Carplay and the Android equivalent. Unlike an old stereo, there's no real option to update it because it's so integrated. I wonder if this is leveling out, though. Smart phones have gone from ~2 year life to ~5 year life.