I bought a used vehicle, mileage wise it was just out of warranty, year wise it was out by 3 years.  I did get an extended factory warranty with it, didn't seem like it cost that much for all it covered and the term limits.  I think it all depends on the situation.  With a new vehicle, you have the warranty that comes with it for a while.  Then it will probably last a good while after that before anything may happen.  I figured buying used, and running it a long while before I trade it, it may or may not pay for itself, but for the minor stuff that breaks or goes wrong with it as it gets older, I don't have to worry about touching it.