It's a well known fact that you should wear gloves while installing sound deadening like this

This gets the job done and then some, I did my entire 2017 WRX (doors, trunk) and my doors have a nice thunk and weight to them, really makes a difference on the inside to reduce road noise and improve sound

decent sound deadener, prefer FatMat

Excellent quality sound barrier

I'm only seeing about a 2dB drop in sound, but the sound that is coming through is much less annoying, which is a little weird to say

Great sound deadening material and not very expensive

Sorry, I won't know how well it actually damps sound for many months.

Very good sound deadening for the money