Don't know if I've had this since day 1 since I've been messing around with the exhaust discs. At cold start and when I rev it to 3000 RPM and higher (stationary and moving), I hear a buzzing/vibration/rattle from the passenger side. I thought it was my imagination, but my wife noticed it too. So, I recently opened the passenger door and brought the RPM up and the noise went away. That tells me it's in the door. I've removed a lot of door panels over the years with no problems (even BMW), but the last door panel I removed, I wound up cracking a plastic hanger on the back (F150). So has anyone out there removed a panel, from a 2010 or newer Mustang, that may be able to give me some tips before I rip this thing apart?