OK, I'll check rubber plugs, but no, no wires that I can see could be at fault.
I forgot to mention something. The car has no rear bumper. Nada. I noticed that on the lift the other day. Behind the bumper skin there is just inches and inches of air. Maybe when the PO ditched the bumper to put on his gay quad exhaust tips, he didn't plug the mounting holes.
Damn thing is so low, and me 6'6" - I keep putting off crawling under there.