use peal and seal ... it is hands down the best product you can use for your roof, it stops leaks, protects your wood, and is a great product to use over tar mat when used under shingles, it can also quiet the sound of rain hitting your roof !!!
as for your car i would use second skin... it is pricey but you get what you pay for !! i used edead45 on my car and it was affective and it did work but it did not kill my exhaust drone or my engine noise. yes it stopped vibration so would any product if you put many layers of duct tape and foil tape on your car it would stop vibration but thats not the only thing second skin does to your car... save up your money like i am doing and do it right the first time like i chose not to do so now im spending my weekends peeling of a shit ton of edead and saving my money for a bunch of different second skin products i will be using together for the best results ...
Use damplifier Pro for your doors roof trunk underbody
Use spectrum to cover your doors better the underbody of your car and wheel wells for added sound deadening/barrier and protect from rust and in the trunk for added sound deadening and sealing off the trunk like i will
use luxury liner pro for the BEST results of a sound barrier on the floor of the car and the floor of your trunk
make your car sound louder and cleaer and when the music is off make her quiet like a Rolls Royce