Originally Posted by CarbonFoot
Buy yourself a roll of foam backed tape and go to town. Rattles drive me absolutely crazy and I've had great success with applying this stuff in key areas of my car. The hardest part is isolating the areas that are causing the problem. It helps if you have a bassy exhaust and helper touching and applying pressure in rattling areas as you blip the throttle or drive.
Now, are we removing panels and stuff to get to the rattle?
Is that where you're applying the foam backed tape?