I've been struggling with my radio for some time now. Unfortunately I can't remove the head unit without a special tool from the dealership. It's going to cost a fortune if I go to the dealership for this issue, and I was wondering if there was any place that can handle an old Mercedez Benz at an affordable price. The problem I believe is that my ground wire is loose or disconnected. I'm under the impression that this is an easy fix, I just don't have the tools necessary. Can I get something like this at Advance Auto Parts?