Dynamat or Fatmat??

Carpet Padding Works Great for Heat & Sound, is cheap & once the carpet/headliner or panel covers it, you don't ever see it again.

Keep Water from Getting In & Getting Trapped & you won't have trouble w/ moisture.

Carpet Padding can be free, or almost free. Foil-backed bubble wrap is crap.
Do you really wanna spend $100 for plastic wrap & potato chip (mylar) bag material?