There was a test done somewhere that found out that you would need 10 times as many layers of peel and seel as actual sound deadener to get the same results.
it will work for what ya got man. i used it in my quarter panels and went up .2 so it does its work. dont scare away from the bad talk. it works, its cheap and it dont smell unless ur RIGHT up on it smelling it. but under panels u will never know