I would suggest you locate an independent Mercedes-Benz repair facility. Those of us that use a local shop for some repairs and/or service similar to yours, take our cars to a shop the works on M-B cars. I've got a really good one near me and I would imagine you could find one also. These shops won't fix anything Chrysler specific, but the chassis & powertrain is M-B's R170 design and they will be able to handle anything required for that model line.