Thanks for the link, an interesting read.
Most people will want to take a simple and cheap approach to sound "improvement".
And if they follow the link and read it, they will see that: "Attempting to reduce road noise by only doing a few areas (like just the doors) is usually a waste of time, effort, and money. The significant gains come the closer you get to 100% coverage."
I didn't realize that sealing the outer skin from inner with ABS plastic was something that is done. Makes sense why it should be done, just never seen it done before on any install.