Stuff is the uncensored word I will use in describing the problem. I bought 4 boxes of this stuff, relying on Eastwood's reputation, on sale with free shipping. The photo shows what some scrap pieces look like after laying on a table in my shop for a few days. The foil literally floated to the side when the sticky goo liquefied. This may not be a problem on floorboards but I had already installed over a box of the stuff under the roof and on the firewall/dash of my 1967 GTO body while it was upside down on a rotisserie. The body is now on the frame and the sticky stuff is running and dripping down while sitting in my 120 degree shop. The interior will get hotter than this when the car sits in the sun and the goo will mess up my new headliner, carpet and other interior items if I install them the way it is. It already messed up my shirt when I leaned into some drips. I emailed Eastwood tech support for a solution but, after several days, got no response. Ironically, one box was to cover my son's 65 GTO floorboards that we originally covered with NAPA auto body undercoating. That stuff is still pliable, sticky and messy after 22 years but at least it doesn't run and drip like this stuff. I am not sure what to do at this point but am planning on trying to seal the stuff some way rather than spend weeks trying to scrape the s*** off. My advice is to avoid this stuff if it is going to be used when hot or around heat.