Most of my car is done in FatMat and XXX. I used a heat gun when putting it on, like I do with any deadener, and I've yet to have any issues. The problem with FatMat is that when it's cold or even room temperature it won't stick. However if you warm it up and then put it on it'll never come off. That's my experience at least. Oh, and I've never had an issue with it smelling after being applied. Again that's just my experience.