A common logical mistake is to assume that when a car's resale value is less than the cost of repairs it is time to scrap the car. Hogwash. I'm not saying that every car is worth putting huge amounts of repair money into, but often a person is in fact much better off keeping what they have maintained and running than they are replacing the car.

A more reasonable point might be to say that when the total annual all inclusive costs of running your existing vehicle exceed the total annual costs of a newer replacement vehicle, then it makes sense to replace. There are many ways to do that math, but it is always more complicated than the simple minded cost of repairs vs. vehicle market value thing so many people do.