I recently installed a sub in my 05 WRX wagon, and the only noticible rattle from the driver's seat is the rearview mirror (auto-dimming with compass). Anyone have any suggestions on how to silence it? Is there a way to take it apart and maybe put some dynamat in it or something like that?

i dont have a sub but i have the mirror thing
mine doesnt rattle but check to make sure its not the wires or the box

I can hold the mirror and the rattle goes away, so I'm certain it is the actual mirror and not the wire.

Mine rattles.

Bump. This keeps getting worse and I'm not really sure what to do about it. Any suggestions???

Take the mirror off the windshield (turn it 90 degrees and it comes off), and check the metal spring inside that holds it in place. The spring may have lost some tension allowing the mirror to rattle. If it has you can probably fix it by bending it slightly, otherwise you can go to a dealer and get a new spring.

I'll give that a shot. Thanks.