ACS/Dorsett offers sound barriers/heat sheilds made out of EVA MassBac then die-cut to fit underneath the floor carpet to help eliminate unwanted road noise and engine heat from entering the passenger compartment.

Here is an example of a Sound Barrier kit for a 1964-68 Ford Mustang. ACS Dorsett offers Sound Barrier Kits for a wide variety of makes and models. Click the photograph to enlarge.