I'd have to agree with the "it depends on the people" view.
For starters, my local BMW dealership is pretty good. Ordered back in March, did one spec change then a correction as they'd left out the folding mirrors but all got sorted. Once or twice I didn't hear anything for a while, but a quick email or call usually got things moving. Delivery date was changed only once (5 week delay) but they kept me informed. Hand-over was good.
As to Audi dealerships, well I'd almost go as far as saying that my experiences with 5 Audi dealerships in Sussex and Surrey has left me feeling I will NEVER again buy an Audi, not even if they gave me a 50% discount!! Utter cowboys who shouldn't even be in business, and Audi UK are no better
Best (and worst) experience I had was with a local Lexus dealership. Bought an IS200 then bought an IS300 and both transactions were faultless - the dealership was really proactive both before and after I got the cars. Interestingly, during my IS300 ownership the dealership changed hands and practically the whole team changed over a period of months, subsequently customer service fell through the floor (to the extent that I had to involve the new dealership manager who was the most arrogant s.o.b. I'd ever encountered) which reinforces my view that it's the people not the brand.
The true test of any dealership is how they look after you when things go wrong and sadly that's where most seem to fall down.