I know this is blasphemy to some of you but I want to reduce road noise and increase SPL a bit. Besides, this car sees more daily driver use than track use so I want to make it more comfortable.
I'm only adding about 40 lbs in total for the trunk, floorboard and doors. Heck, I think I remove 10lbs of dirt and the PO had glued the grey carpet over the OEM black so I was carrying two layers of carpet.
The difference is a nice thud as opposed to a ring when tapping on the door sheet metal. My new Boston Accoustics should sound nice in there.