I had put dynamat in the same place on the trunk lid on my 98 Mystique due to ratteling from the same sub. I just threw it on the '00 'cause I knew that's where a lot of ratteling comes from (my Mystique didn't vibrate too much after that, and I never even did the rest of the trunk on that one). The rest of the trunk still saw a huge improvement after spraying it down and all, though.
Yeah, that link is essentially what you want to do, all though that's a bit overkill.
Check out the Sound Deadoning link on this page:
TeamROCS Technical stuff
