We usually suggest you see a local shop that does Mercedes. In fact, that's what I do.

But for a CPS or sticky ignition key and a lot of other items - you can just print our tutorials and let the guy, any shadetree mechanic, follow them.
Saves tons of money. The BIG problem with cars today is electronic diagnostics. No one teaches how to trouble shoot electronics in cars (or in general).
When you add the fact that these cars are Mercedes and you are taking them to a Chrysler dealer - horror results.

I wish we could get the message out to NOT take these to Chrysler dealers... there are MANY better options.