Ok which is the most bang for the buck? Dynamat, Second Skin or the rest?
Brian

WHAT? I can't hear you over my lound old car

I would think dynamat on the rear bulkhead under the backpad. Maybe some on the floor and doors (I think you just need small pieces to absorb the vibration, not the entire section)

Also make sure your rear window is sealed, all weather stripping is good, and you run stock-ish muffler and air cleaner.

I used Fatmat (50 mil) and am pleased with the results.

I used Dynamat after researching the others.. Some of these products are derived from roofing materials and smell like asphalt when warm. Some also fail to stay put in the heat.
Best price I found on Dynamat was on Amazon. The difference is remarkable. I applied it to both sides of the rear firewall under the pads, in the doors and the front firewall areas.
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I have used Lizard skin both insulation form and sound form and have been really happy with it.

There definitely is much info online about Dynamat vs. competitors. I was wary at first about FatMat because there were some older reviews that mentioned the tar smell, especially in hotter temps, but I haven't experienced that. My main reason for going with FatMat was cost and also recent reviews that were more favorable regarding the smell, adhesion, etc.

Cheap and easy is the Peel-n-seal from Lowes. Did my dd, doors and body behind the speakers. Only smells if it's fresh, gone in 24 hours. I think the heat only makes it stick better and I've got the heat.

I've done both Peel and Seal and most recently Raatmat. Peel and Seal I did for years and had no issue with it does smell for the first few days. Supposedly in really hot or col climates it can de-adhere to the metal. I'm not sure if I've experienced that as I've not pulled off my door panels yet.

I recently decided to spend a bit extra for the good stuff as it was going in the Porsche so I bought RAAmat with Ensolite over the top and couldn't be happier. Much more pliable and easy to apply. It made more of an impact than the peel and seal but that could be the addition of Ensolite over the top. This stuff is made out of butyl vs. the asphault that Peel and Seal is made of. Here's the package I got, it covered the entire interior of the car with a bit to spare and double up on. http://www.raamaudio.com/package-2-30-shee...-ensolite-foam/ . It's a bit pricey but the Peel and Seal will add up really quickly as well. FYI if you go this route do not put Ensolite on the floors or interior of door wells it will absorb water. I put the Ensolite over the RAAmat on the interior engine bulkhead, over the exterior of the doors immediately under the door panels and everywhere I could reach under the dash.

FYI from what I hear FatMat is a repackage of Peel and Seal with a higher cost, apparently side by side they are nearly indistinguishable. No first hand knowledge I just read that time and time again after hours of research.

Good luck!

+ 1 from LOWES...no issues. No smell and stays put.