I recently had some body work done which entailed removeing the back window. When I got my car back the AM radio was complete static. The shop guy told me to bring it back in and they would fix it. Just picked it back up and I can hear the radio now but there is still background static. Does anyone know what the problem could be? The body shop guy said it was a bad ground connection. Is there antenna wires running through the back window (kinda like the rear defrost)? Thanks!