I went with RAAMat for mine, and wound up ordering 2 of their 37.5 sq ft kits (20 sheets ea with the accompanying Ensolite foam sheet material). It was cheaper comparitively priced against Dynamat - probably because it doesn't have 'Dynamat' logos everywhere (that costs more money, after all). I've seen Dynamat up close, and it's pretty much the same thing. With the two kits, I was able to complete the firewall, kick panel area, floor, and roof with approximately half of the 2nd kit remaining. I didn't use the Ensolite on the floor, since the carpet has jute/mass backing, as well as I installed some repop factory-style roof insulation before the headliner went in.
Since full coverage of the BXT II material (butile-backed aluminum sheets) isn't actually required for sound dampening (more like for thermal barrier protection), I should still have enough to do the insides of the doors, quarters, and trunk area. However, I did do full coverage on the firewall, floor, and roof areas to make a complete thermal barrier, because of the engine, exhaust, and West Texas sun.
Using the strategic 'strip' method (cut the sheets into 2" wide strips, and place them strategically on the inside of the exterior sheet metal) the placement and weight of the material will drastically cut down on the vibration-causing noise. The real sound deadening performance comes from the Ensolite material, being placed under the interior trim panels, much like the moisture barrier sheets (replacing them, ideally), sealing up the holes in the interior door panels, quarter panels, and trunk barrier.
I started with the firewall and made my way back:
Still need to do the doors, but here's the floor done with the HVAC installed:
Here's a link to their "How To" page: http://www.raamaudio.com/pages/How%252dTo.html
I do not think it is worth the time and money to do all that. Unless it is going to be a daily driver you use all the time why bother. I did put some on the cowl only because the original had all fell off like most have.
For the few times I go to shows and what little I use the car not worth the effort.
You put a loud exhaust system on then try to make it quiet, lol.
I never had an issue with noise in any of mine or heat or cold. I think people are just being sold up to using it by the mfg..
You would be surprised at the difference of car noise levels between stock and 'with deadener added.' I'm not talking about loud exhaust noises, either. Large panels of sheet metal tend to be flexible enough to vibrate, causing 'white noise' types of extra noise to be added to the barrage of audio being thrown at the passengers as they drive the car. The foil/butile-backed material (BXT II) disrupts the vibrations and helps eliminate some of that extra noise. The addition of the foam (Ensolite) just helps diffuse those sounds even further.
If you were to tap on any of the exterior sheet metal panels of any of your Mustangs, you would receive a very tinny-sounding 'bong' sound - which indicates the ability for the sheet metal panels to vibrate and produce the noises I mentioned.
If you were to tap on, say, the roof of my '71 that's been treated with sound dampening materials, you would receive a very solid-sounding 'thud' - which indicates the ability for that sheet metal panel to vibrate and produce those noises has been greatly reduced... which goes a long way toward reducing 'road noises.'
It's the same principle as grabbing a bottle of aspirin by the lid and shaking it - you hear the pills rattling around inside very clearly and loudly. But if you wrap your hand around the body of the bottle and shake it, you'll still hear the pills rattling around inside, just not nearly as pronouced or loud.
The other big benefit of the BXT II material would be as a thermal barrier. Yes, I installed an aftermarket dual-exhaust system with headers, which by all means would be expected to generate more heat. Even though the headers are ceramic-coated and seem to produce less heat than factory exhaust manifolds (side-by-side comparison with a laser thermometer demonstrated that for me), I wanted the extra benefit as well. The same goes for the roof, since I also installed A/C (a must in West Texas) and want it to work as efficiently as possible.
I recently (5 years ago) had the roof redone on my house, and went with some impact-resistant shingles and underlayment - which, coincidentally has a 'foil' side which is purported to also be a thermal barrier. Was it more expensive? You bet - almost 3X the cost of R & R of standard shingles... but it also cut our electric bill by 70% (was scrapin' $400-ish in the summers, but now rarely has gone above $150 even during the triple-digit temperature summer months of endless A/C). I've already recouped my investment in the form of saved electric bill money. What can I say - I'm a believer.
I love the sound of my car, and I've never driven it (so far) without the windows being rolled down. I'm a realist, because I'm aware that the car is an almost 50 year old muscle car - it will never be "modern luxury car" quiet inside... nor would I ever want that. But there's also nothing wrong with making the car a little more palatable for my wife, who always makes comments regarding how loud it is and how much it stinks (old car "carbureted" exhaust, after all).