I am looking to quiet down the van and insulate from heat. I found this Ultramat stuff on ebay, mistakenly thinking it was self adhesive, and since it was inexpensive, I bought two packages, 60 sq ft. You don't get the instructions until after you get the product, the instructions say to 1. use spray adhesive, 2. tape the edges or 3. snug fit. I have a can of spray adhesive, would that hold up to the heat and potential cold so this stuff doesn't fall down? anyone else tried this method or should I just return it and buy the self adhesive stuff. I did some searching and it looks like the water proof falshing sold at Lowe's etc. might be a cheap fix as well.