Would there be any advantage to covering the 1/2" spacer in Dynamat Extreme?

 

No but covering the entire rear deck lid and running it up and around the spacer will definitely help.

Here's a pic to give you an idea of how to lay the dynamat. BTW, buy Cascade sound dampening. It's great and has no odor like dynamat.

 

cool. i'll add that to the list. can't wait to get time to get this going thanks