I was determined to figure this out today, but it still got the best of me. Here is what my (plus my passengers) observation was:
- "chirp sound" is coming from passenger side rear door it seems
- Happens when cruising anywhere from 30+ regardless of road quality
- If rear windows & window shade is up (front windows down) it seems to go away
I taped the rear window shade area down with tape and it seemed to help but I didn't have a passenger when I did that. Seemed to be a bit less noticeable when I rolled the rear windows up slightly.
Someone solve this riddle (the M6GC folks will thank you)!
We looked over the rear seat belt and thought it could be the rear speaker by the window but here is again where we feel the sound is coming from:
