UnderCoverNinja

I recently got my car back from the body shop from having my rear bumper replaced due to a very minor rear end crash. Now i noticed my radio AM and FM radio reception is not as good/ clear anymore. I am assuming perhaps a ground or some sort might of been disconnected and possibly never put back on properly. Any suggestions what it could be..? or does anyone have access to a antenna wire diagram that i could review and attempt to locate the problem.

Thank you in advance !

KEY08

The antennae is in the glass. rear window

nota_amg

MB used to use a small filter/signal-amplifier for the antenna, should in the trunk somewhere. Possible that was left unplugged from power? Not positive where it is in the w212, sorry