How to stop rattles in trunk

How do I stop the rattles in my trunk?? I got some subs that hit hard, vibrate the trunk and annoys the piss out of me!! I need to know everything you can do to stop the rattle. I am going today to get rubber washers to put behind the bolts on the lisence plate. And I'm also getting some rubber hosing to put around the edge of the plate. The inside of the trunk lid rattles too. Any suggestions would be greatly appreciated. I hope this helps other people too. Also...my rear view mirror makes a rattling noise too. How do I stop it?!?!!? Thanks