Well it is good at damping which is what I used it for. The drone; as any drone for that matter, was cause from the resonance of the vehicles natural harmonics; my car's drone kicked in at highway speeds. By dampening the thin sheet metal in the car from front to back as I did helped removed most of the resonance by not letting the metal vibrate as much. As for doing more than the needed 25% coverage; overkill is overkill. It worked; using more didn't reverse the effect of what it was for. Factor sound deadening is done in just patches; I am sure following the 25% rule. It did sound deaden the car because once you opened up a door or rolled down a window it got much louder and unmuffled. Before the deadening the whole car would rattle and squeak as most do with a large amount of bass, and could be heard a lot more outside of the vehicle; it was very quiet outside of the car after the install. Right or wrong method applied to putting it in the car; lots of people do it I am sure, I still got the results I was after which is what matters most. To each his own I guess.

 

RAAMmat BXT is good quality stuff and butyl based, not asphalt. I've has Fat mat in the past and it melted in the AZ sun. May have improved since, but I won't risk it. As for the doors, mine were nearly 7lbs heaver each after I was done. Definitely makes a difference.