Dyno mat???

Hey guys I just purchased a product similar to dyno mat and wanted to know all the common areas that folks apply it to. I of course am looking to reduce heat and noise. I already plan to put some up under near the firewall. How far down the interior would be good. Should I cover the entire area that the carpet will lay? Is it necessary for the trunk area? Thanks for your ideas and experiences guys. Btw I own a 73 dart sport
Author: kfrese