Two thoughts:
State insurance commissioner
Local "investigative" media--newspaper or TV most likely. Some of these really like digging into this stuff, especially when it starts looking like collusion between/among the claim adjuster, the shop, and/or the insurance company. It doesn't help that you have a Mercedes, but it does help that it's not brand new and you've been trying to resolve this on your own, etc. etc. It may even be enough to say to the adjuster, "Here's what we're going to do: First, we're going to stipulate that the car was in proper order before the accident, which it in fact was, and that anything wrong now is the result either of the accident or the inept work at your shop, which in fact it is. Second, the local MB expert is going to fix this, and your company is going to cover it, since the repairs weren't done properly at the shop you identified, and they clearly don't have the expertise to work on this car. Your other choice is to explain to TV13 why we've got all this weird stuff between you and XYZ shop, as well as a car that has stuff broken that was ok when it went in. Your call..."

For future reference, find the really good shops in your area, and what insurers they work with. Some of them may actually have good relations with your insurer; one of the very best and most respected around here is an approved shop for AAA, which means that my AAA coverage kicks in without an adjuster having to get involved at all and they automatically accept the shop's word--all of which goes away if AAA gets even a whiff of abuse, which is the incentive to keep it all clean. There's also a fairly meaningful warranty on the work.

Good luck with it all! And DO report to your local Better Business Bureau.

__________________
Craig Bethune

'97 SL500, 40th anniversary edition

'04 Olds Bravada (SWMBO's)
'06 Lexus ES330
'89 560SL (sold)


SL--Anything else is just a Mercedes.
(Kudos to whoever said it first)