If you want a superior quality and look's go with Line-X. Its a truck bed liner, it has numerous applications and it works fabulous. I had it sprayed in my trunk of my Evolution MR to reduce exterior noise and rattle from four twelve inch subwoofers. I've read numerous articles on this product, one was the pentagon uses it to line their walls due to it's sound deading properties. I was going to use dynamat but after reccomendations from other people that have used it I was sold.
Heres a good link to get you reading.
http://www2.line-x.com/ns/news.html?NewsID=191