Bimmer's is excellent for most things.I would try Bimmer's in Kennesaw, GA.
2486 S Main St
Suite B, Kennesaw, GA 30144
They have done me right so far. If you are closer to Alpharetta I have heard of a great shop over there too but have not experienced them myself.
11090 Old Roswell Road, Alpharetta, GA <nobr>(770) 641-6202 I have heard they have a great tech.