Auto Talent is hands down the best shop that will cater to all your needs.
Sam is really helpful and Zolti is probably one of the most competent technicians on this planet, seriously.
As for LA, welcome!
It is a great place to own a performance car such as the M3.
It will take some time to adjust to the completely different city infrastructure but there's a lot to like.
2013 E92 M3 6MT ZCP Space Grey/Fox Red