Sound deadening?

[castellscl]

So I was putting in my new stereo this past weekend and found out I had a puddle of water in my floor board (A/C drain clogged). I had to take my carpet out to get it nice and dry. While it’s out, I figure I might as well put down some sound deadener and absorbing mats.

I did the doors a few years ago, but still need to do the floor and back panel.

My question is, how much material would I need to cover the floorboard once and the back panel twice?

I’m going to put this down first:
https://www.b-quiet.com/ultimate.html

and them maybe some of this:
B-Quiet sound deadening materials - B-Quiet Vcomp

How much of each would I need?

 

[SID297]

I don't know the exact amount, but it should be pretty easy to figure out. Just measure the cab and calculate the square footage.