For a BMW independent, I suggest starting with Ramon and Nicole in Milpitas:
Bavarian Motorsport | Bavarian Motorsport BMW Service and Repair in the Bay Area since 2002
They are very active with CCA.
I have known Ramon for probably 15-20 years by now.
The CCA chapter here is I think the largest in the US.
If you need top shelf help from a dealer, the number one man at Peter Pan is in my network. he only works on special projects I reckon.
I have not been to Stuttgart since 1996-- was there when the Boxster was being launched here.
Special factory tour at PAG and Octoberfest.
In case you get home sick in MT. View:
https://www.dittmers.com/