Looking to quiet the cab down a little, and hopefully tighten up the stereo sound. Went and talked to stereo shop and he priced me on 2. 5 gallons of Dynomat spray in sound insulation that comes with the gun to hook up to an air compressor. Priced me at $150 and I trust him when he told me that was a good price. Noticed the other day that some undercoating I had laying around the garage claimed to deaden sound and road noise. Any opinions on the Dynomat spray? Should I spend the extra money on the Dynomat or try and get out the "cheap" way? Or should I forget the spray and get some 1/2" foam insulation? Looking to do basically the WHOLE cab and do it right the first time.