Silvio,

Precision Mercedes
http://www.precisionmercedessantacruz.com/

Circle Star Motors
http://www.circlestarmotors.com/

These are in the soquel area near Santa Cruz. I think Circle Star is very good on the newer cars. I have my wife's 2006 E class wagon serviced there and Max, the owner, is great to work with.

Precision Mercedes I have heard is very good on the older cars.

Ricardo