I ordered Fat Mat extreme. Much cheaper than Dynamat, and close to being exactly the same product, IMHO. The hair dryer is a must ! The tar heats up and the material becomes much more flexable.
What I learned applying Fat Mat to an Astro Van -
1. The back of a screwdriver is needed for tight areas. Use a roller on larger areas.
2. Apply two layers where there are large gaps between metal surfaces.
3. If you don't have a hairdryer, lay the sheets out in direct sunlight and wait about an hour. Same effect as a hairdryer, just takes longer.
4. Use gloves when smothing out the edges of the Dyanmat. You will have cuts on your fingers, and a ton of scratches if you don't.
5. After appling the first layer, tap the outside sheet metal, if it sounds tinny and you can here a vibration, apply more material. My Astro took up to 3 layers in some of the open areas to eliminate the vibrations.
6. Once the material is applied, it's NOT coming off. Measure twice, cut once !
Hope this helps !
The Big E.