There are other thermal barrier products out there, if you search, you can find them. Most are competing with Dynamat, so will be cheaper. But most have little feedback, or at least at the time I did my homework, so I gave up. There are people out there that have done pretty good comparisons of products, one I think was on the pro-touring site, search it. There's different types of thermal barriers too, ones for deflecting heat, etc, and choosing the right one for what you're trying to do makes a difference.
Doors - No, because I reasoned, 1) with the acoustical mat, and the panel, a decent amount of thermal insulation would occur, and 2) the Dynaliner would have added enough thickness (the way I applied) that the door panel may not fit correctly. (Keep in mind, the majority of the radiant heat comes from the firewall and floors, especially from the muffler area. You can wrap the mufflers if you want more, and the exhaust, but it will make your exhaust rot faster).
Roof - Black car. I wanted to do something to the roof, but, it had the OE stuff on the roof, those panels of thick, asbestos-looking crap, and, honestly, I didn't want to mess with it! They were still intact, and I know it would have made a mess trying to gut it. Plust those braces are in the way. If that stuff is moist, or looks stained and rotted, you have no choice, but on this car, there was no evidence of moisture, so I left it.
Door Panels - Think I covered that. I really feel the mat and the door panel is enough to block most of the heat. You're not going to get much radiant heat from the center of the door, there's a pretty big air gap there. Air conditioning will mask anything that isn't blocked by the panel.
I bought 2 boxes of the Dynamat, bulk pack, and think I got each for like $115. That was from a place that offered free shipping, which will KILL you with that stuff, so keep that in mind when shopping it. Find a place that is as close as possible to you to order from, and even if it's like $20 or something more than another place, you may save it because of shipping.
Just checked, StreetSideAuto.com still has free shipping on it, and the 9-pak is $134. They have the liner too, which comes in different thicknesses:
http://www.streetsideauto.com/search...ywords=dynamat
Might be able to find it cheaper, shop it some...
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