I have this sound every once in awhile.... it's not a persistant, on going sound, coming out of somewhere near my rear speakers. Its a weird noise that seems to mimick the sound of my car. As in, if i accelerate, the noise becomes louder and a little more highpitched. Otherwise if its at rest its just a low rumble/vibrating noise. Its really diffiicult to describe. If I hit a bump or something in the road it will instantly stop making the noise, but if if hit something else or take a turn or something sometimes it will start over. Any help you guys can give me on what it is, and how much it should cost to get it taken care of, I would really appreciate it.

AO

 

It sounds like a bad ground or loose positive cable. Check the speakers on all four doors. The front will affect the rear for some reason.