Hey Bryan,
I can't give you a good estimate on costs as I installed the Dynamat about four years ago and do not remember exactly what it cost at the time.
Suggested retail pricing can be found through Crutchfield:
http://www.crutchfield.com/S-B8ybJEw0xsV/cgi-bin/ProdGroup.asp?g=181250
Do a search on Ebay - Lot's of deals for up to 50% off.
Depending upon how much and where you apply Dynamat the results can be dramatic. Rear wheel wells and doors probably give the most bang for the buck. Water noise from wet roads almost disappears as does much of the tire sound.
As taken from the Dynmat site:
"How much will Dynamat quiet my car?
Even a small amount of Dynamat can cause a profound noise reduction. For example, applying Dynamat to the doors of your vehicle can reduce road noise from 3-6dB!. Complete coverage of an average vehicle can reduce road noise 9, 12 even as much as 18dB."
Those are some big numbers which I'll support following installations on four vehicles: '96 Saab, '99 Suburban, '97 FZJ80, & '82 FJ40. The 40 provided the most impressive results with the truck going from amazingly loud (swampers) to just plain loud.
You can go nuts and spend hundreds on this stuff, but you only need to be strategic in where you install it and the results will be very apparent.
If you have a decent stereo in the vehicle, a few $$$ of Dynamat can make it sound as if you installed new/better speakers. By 'deadening' the vehicle and the vehicle structure around the speaker locations, the speakers do not have to compete (as much) with road noise and vibrational noise transmitted through the vehicle. Doing this can make a stock stereo system sound much better and an aftermarket system sound amazing.
The last major advantage of Dynamat is its insulating qualities and its ability to reflect heat. In the 80, I placed a couple layers of Dynamat on the floor, tranny hump, and front seat on the passenger side where the floor would get very hot from the cats. Following this install, the floor only got warm to the touch. I've sinced replaced the cats with a high-flow cat and the heat problem dissapated. The insulating qualities were best noticed on the 40. The truck used to be extremely hot to wheel in when sitting and idling or running slowly for long stretches of time in the summer. The heat from the firewall and floors was wicked
. After installing the Dynamat, the truck runs MUCH cooler
as most of the heat is reflected downward instead of being obsorbed by the truck.
Be sure to use the correct Dynamat for what you're trying to achieve. There are many different kinds for different applications.
HTH's
Randy
