hey i have an 06 mustang

and 2 12 inch subs in the trunk...anyone have this setup
the problem is the spoiler shakes a lot...and ideas how to fix that...

Dynamat your trunk and include the lid.

yup...i dynamatted the trunk lid, and around the bottom part of the trunk also. it makes a huge difference in the rattle factor and also the tightness of the bass! I couldnt believe how good my little 10 inch infinity perfect sub sounds! definitely the way to go!
http://i18.tinypic.com/2mnpr2w.jpg

will the dynomat help the rattle of the spoiler or just the rattle of the trunk lid

yes it should hold in all the sound in the trunk. it deadens the rattles....if you knock on the trunk its surprisingly solid after applying the dynamat. It will make a nice difference for you. I dont want to say it will take care of it 100% though. I got a buddy with a JL 13w7 in his trunk with 2 layers of dynamat and it still rattles, but that sub pounds big time haha. Its a step in the right direction though.

how much will it cost for the whole trunk

well, i got the dynamat because i get a discount on it at work, but other wise it can be pricey. The whole trunk would be probably $100 at retail. Look online also for discounted prices as i am sure there are some out there that i just havnt bothered to look for. also look at secondskinaudio.com. they make a similar product that i have heard good things about and its very reasonably priced. hope that helps.

yeah i used to work at bestbuy
and i know the discount was good for that

im gonna see if my friend can hook me up with some..