Thought about putting this in open discussion, but there's too much politics, ornery debate and other stuff over there. Since my question actually involves cars, here it is:

How do you decide it's time to replace your existing car? Everybody must have a method/formula/rationalization for this process; let's hear it!

My not-entirely-tongue-in-cheek method is this. When the guys behind the parts counter at the local dealer know my name, recognize my face, have memorized that I drive a 124.193, and can tell my voice on the phone, then I need a new car. At that point I'm obviously spending too much time, effort, and money on fixing the old car. In the interest of having a life (I do! really...) it's time to get something that needs less TLC. I almost reached this point during the air-condition-ectomy last winter, but I think they've since forgotten me.

Let's hear your thoughts on the matter.

- JimY