Actually I used Rammat. Its not only cheaper but its better. I bought 2 rolls which are 62.5 sqft for about a $100.00 a roll. Plus I bought 6 yards of ensolite foam barrier that is glued to the Rammat.
RAAMaudio
I had it applied double layer in the trunk floor and wheel wells and yes, both doors. It was very well worth it as the car is amazingly quiet inside.
I had the entire interior of the car removed. I am adding pictures of the process on the Audio thread but there are a few there already.