If anyone has a solution for this, I would be eternally grateful.

I have been trying to solve this for years now, but no luck as of yet. The rattle I'm hearing only returns when it's cold out (40 degrees F or so). When I set out on my morning commute to work, I hear a semi high frequency rattle or buzz emanating from the rear deck or possibly inside the trunk. It's not too loud, but it's loud enough to be a real annoyance.

So far, my efforts to eliminate the sound have been to install Dynamat on the top surface of the rear deck to isolate the plastic deck cover (thought it was the plastic deck cover against the metal deck), disassemble/reassemble ALL components of the trunk lid (thought I had it when I found one of the nuts securing the taillight assembly was loose, but no), and insert pieces of paper in each of the plastic covers for the child restraint anchors. It is worthy of note that this rattle/buzz goes away after the car/interior warms up each day.

I can't get anyone (yet) to ride with me during these conditions, so I can't really isolate the location of the sound yet. The sound appears to be metallic in nature, but it could be metal and plastic against each other. At one point, I thought it could have been in one of the speakers, but then I'd think I would hear it whenever I play the stereo, which isn't the case.

Feedback/ideas? Thanks again!

 

The hangers on the muffle have been known to be bad, maybe its that