In the end, I think dealerships are like the install shops at Best Buy and Circuit City.
You might find someone by chance that does good work. There are a few.
But the system in place does not incentivize good work, it incentivizes sloppy, fast work - and if you get good work, it's in spite of the system, not because of the system.
So the work product is tied to the person, not the system - or in this case, the sign over the service drive.