Bill Barber,
I don't think I explained myself well, dealerships "fix" things by replacing whole parts. For instance, my uncle just worked on a transmission (his speciality), the owner originally took it to a dealer and they wanted to replace the whole transmission for a good chunk of change. My uncle pulled it and rebuilt for a whole lot less!
We dealt with an issue on our minivan, which is out of warranty. The kept replacing parts as a process of elimination. I remember sitting around watching family and friends work on cars as a kid, they would spend so much time listening, diagnosing, and trying to figure out the problem. Nowadays it is hooked up to a computer and parts are replaced according to what the computer says.
I was experiencing a problem with my ST and took it to the dealer several times and the computer didn't say anything. I took it to another dealer and the guy working on it said that it didn't register anything on the computer, but he happened to notice the engine skipping as it was sitting and idling. He looked into it and discovered the problem! No computer needed!
Anyway, dealers don't tear things apart and rebuild (or fix), they just replace parts and go on. Rebuilding saves the consumer a lot of money!