I used Dynamat on the entire interior of my Jeep. It helps, doesn't make it quiet by any means. They have off-brand Dynamat that is supposed to do the same thing but is cheaper. One is called Second Skin. I know a lot of guys like that stuff too. Maybe take a look at stuff like that...
![My Two Cents :twocents:](https://board.marlincrawler.com/Smileys/marlin/twocents.gif)