If you can't do it yourself, go find a "German Car Garage" that works on Mercedes (most do Mercedes and BMW). The engine/chassis/etc is an R170, same as the SLK320 - there is no "Chrysler" in the car when it comes to engine/chassis.
It's not a hard job. But I agree with others, I'd want to start the engine and verify that the alternator is not charging - altho alternator fails have become REALLY common as the cars have aged.