Got my Audi A5 detailed here last week and I could not be happier with the results. Wash, claybar, polish, paint sealant, buff and wax. They had had a real understanding of how to approach all of my concerns - water spots, fine scratches, overspray, etc. They had special products to deal with a black finish.
I didn't know what to expect, but the results were beyond what I was hoping for - a complete 180. I think it was a bigger job than they were expecting (black cars are especially difficult) but they didn't slack on anything. I'll be taking my car here again.