Over the last couple of weeks I've noticed a really annoying chirping sound develop inside the car. It's really difficult to tell exactly what it is, but it sounds sort of like a metal on metal contact or even a bad speaker. The thing is, it only happens when I'm moving and it doesn't matter if the stereo is on or off. From what I can tell it's coming from the passenger side behind the seat -- somewhere in the area of the passenger speaker (right next to the seat back) and the support brace / cargo cover bar.
I thought the speaker might be bad but it seems to sound just fine and happens whether the stereo is on or off.
Also, I haven't noticed the chirping when I have a passenger in the car. I don't know if it's just because I'm talking to them or we have the radio up or if this could be an issue with the seat.
Any ideas before I go tear the car apart? It's desperately annoying.
This is on an M6 Touring/Sport.
