Talked with Jennifer at Scosche Industries in Oxnard, CA about their "Accumat" sound/heat insulation material. She is sending me via snail mail a sample and some additional literature on the product.
I indicated the intended purpose and she felt that it would be a viable solution. Per her information over the phone, it can be used for interior panels, under carpet and hoods, and can withstand temperatures from -40F to +250F.
I should have the information by Thursday. I can forward it to you since you are much further along than I am if you send me your address through my e-mail as listed in my profile.
Again, the name of the company is
Scosche Industris
1550 Pacific Ave.
Channel Islands, CA 93033
1-800-363-4490 web page