Trouble with getting more complicated, I’m not at all convinced even the main dealers are that competent, simply relying on the diagnostic port to tell them if anythings wrong.
Volvo, to their credit, have been good, no real complaints at all with dealer service. But VW have been a nightmare, completely incapable of resolving any faults, unless spoon-fed a diagnosis by the computer. I suspect we could put the polo in for service with just three wheels. And unless the OBD diagnostics explicitly reported “wheel missing”, we’d get it back still on three wheels, with a free cup of tea in the waiting room, and an assurance that they’ve run a full diagnostic check and “everything is fine with the car”.
Or more likely, the missing wheel would trigger an ABS fault so they’d fit a new ABS sensor, or maybe an even more expensive ABS controller before returning the car, and asking us to see how it goes, still on three wheels.
We have actually transferred allegiance to an independent specialist for the Polo, with much better experience.