You ask about Dynamat...don't know but here's what I know about Rattletrap...a similar product.
I got a 100 SF roll of Rattletrap. Rattletrap is the thicker version of the FatMat brand. It's supposed to be 80 mils think. The regular Fatmat is about half as thick. Here's the web site. $139 plus shipping.
I think Dynamat is about the same thickness.
I totally stripped the interior. Might as well do it...cause you wont want to go through it twice. Double up where you can.
Made a tremendous difference in 'noise' suppression. Same with insulating. Mine has a little smell right now when closed up. I think it will go away.
Sending you this as a comparision.