Took it to a very good auto electric shop with much MB experience (naturally). Battery drains overnight. They checked every fuse and no problems there. No light on in trunk, etc. He bought an aftermarket OVR from a source he has always had luck with because MB wanted about a million dollars for one. Part number was correct. When installed, the drain stopped but the car wouldn’t start. Wrong relay? Bad relay? Not the problem? Any ideas much appreciated.