Well James, welcome to the board. I don't know about indy mech in Cali. Why don't you get an estimate from the guy you took it to. Then take it to the dealer or call them just to get a bench mark. Then Look into shops in your area that advertise European repairs and call them for a price.
Maybe others from your area may chime in.
How about
OEM / Performance Parts for Audi, BMW, Mercedes Benz, Mini, Porsche & Volkswagen - ECS Tuning the vendor here. They have installers, I think around the country they can reccomend.