Any roofing supplier can get you or sell you a product called Peel and Seal. It is an adhesive backed aluminized butyl rubber material. I have used it and actually compared it to Dynamat and it appears identical. Lowes home improvement store also carries it but only in 6"x25' rolls. I purchased a 36"x30' roll from a Mobile home manufacturer for $89 plus shipping. Most of the high dollar products marketed for insulation for street rods are nothing more than commercially available products that have 200% to 500% price markup and repackaged to make them look like they are made specifically for street rodders.