Try MPH Automotive: http://www.mphauto.com/
I have known the owner Michael Haven through the technical forums we both belong and through our mutual association with Bosch as Bosch authorized Service Centers (BSCs). When I bought my 97 540i through ebay I had confidence that I could get it checked locally in Houston. He told exactly as it was, even caught a catalyst problem that I got the dealer to warrantee five months later when the noise got bad enough to take it in. When I picked up my car I drove out to see his shop. Well equipped is my impression. Well equipped with equipment and well equipped with intelligent staff.
He is on the west side of town and it is a big town.