I have an 05 and I had an obnoxious clicking/rattling noise coming from the rear lid where the speakers are. Anyways after trying to stop it for a while I eventually went into the trunk and unclipped the carpet looking material from under the lid and saw that a wire was not connected to the plug it was supposed to go in.

When I got my windows tinted the guy obviosuly unplugged this wire to get to the rear window and as a result the wire and clip were constantly clicking and rattling as I drove. Once I plugged it back in the clicking went totally away. Turns out the wire that was unplugged was the center brake light on the rear window. Anyways check that wire. Hope that helps