I can tell from the photos this is the same stuff we use to cover refrigeration lines with . It comes in 3/8 to 6" x 5' pieces and it's also what we use in sheet form to wrap the exterior of centrifugal and reciprocating chiller evaporator barrels and comes in large sheets from 1/2 to 1" thickness. It really isn't intended to be glued on to ahe surface, but just a light adhesive to hold it in place so the end joints can be glued together with VASCOCEL ADHESIVE which helps seal the open ends and is really what seals it. It will eventually tear away from any glue backing if moisture is present thus tearing off the surface where the glue is. Its a breeding ground for mold and mildew and will also hold heat in the cabin. However it is a sound barrier and temp barrier and has a 25/50 smoke fire rating but when it burns it smokes bad , don't be around and don't breath it , It will overcome you instantly meaning you won't get a chance for a second full breath. I know Ive caught it on fire with the torch several times. When you push your finger into a sheet covering a sweating chiller barrel in summer you will get some water / sponge effect and usually when it peels off the barrell is completely rusted underneath paint and all is peeled off. The stuff is soft and comfortable though and if you start having these issues just tear it out and use it in your toolboxes. I saw another issue with your a/c . You should build a plenum box off the back hot air condenser discharge same size as coil and at least 16" deep. You can make it from metal or thin veneer and foil tape it . Then come off the box with some flex duct and a small high rpm inline 120v fan and duct it out your cowl vent. that hot discharge buildup in the chainlocker will burn up the compressor and its getting forced into the cabin your trying to cool. But don't close off the opening around the unit/ chainlocker because the condenser intake is on the sides in the rear. The cooler cabin air will make it happy