That list above is ok, imo...but leaves out a couple of very good BMW oriented Indy shops, imo.
To the OP: I'd GOOG "BMW repair shops", in your area and,
also walk up to any BMW/PCar owner and ask where they get
their work done, (skipping Biff & Buffy parked in front of the
"Nails Done" shop
).
Also, if you are a member of BMW CCA, their local monthly
rag for your area, will have Indie ads.
GL,mD