Takes about 2 hours.
Got dynamatt from e-bay $100.00
after removing the child seat tethers, remove the rear speakers, as well as the plastic housing. then fold down the rear seats and remove the black plastic trim at the base of the parcel shelf. to do this you will need to push in the little pin at the center of each plastic rivet. chances are you will lose this little pin, so buy some replacements rivets. after you remove the plastic trim, you will need to remove the rear interior lights. just work a small screwdriver around the edges and it will pop out. then remove the pillar molding. once this is all removed, the parcel shelf should slide right out. my suggestion is to dynamat the underside of this shelf, and then later, once everything is reinstalled, wedge a little open cell foam up into the sub openings. this should take care of rattles, and the sub should not sound too muffled. good luck.
that when RAAMmatting the rear deck, Loki put two layers at the edge of the rear deck where it fits into the rear vent to prevent the rattle. This isn't shown in that pic (did that afterward).
The little rivets are simple, but they break easily so be careful.
The rivets are a push-pin design. You actually take a little nail and push the center in about 1/16-1/8 of an inch and then get your fingernails under the outside of the rivet and pull it out.
To replace the rivet, reverse the pin from being recessed to a raised position. Insert the rivet until the outside circumference is is flush with the panel and then push the center pin in until it's flush with the outside ring of the rivet.