I noticed that the vibration in my doors seems to come from the plastic backing plates that are clipped behind the interior door handles. How do I safely remove these plates so that I can stick some foam or cardboard in the back? I tried using a small screwdriver but it wouldn't budge.
THANKS!!! I pried them off carefully using a normal flat head screwdriver and applied some closed-cell weatherstrip foam. Since there's no risk of the foam slipping and falling behind the door panel, I used several strips and squished the panel into the trim recess. Hopefully it's not too thick and doesn't cause the tabs to "break" or wear down. It seemed like it was made of really cheap ABS plastic. This will hopefully kill the weird rattle/vibration I kept hearing from the door.