Yes if your carpet has padding it goes over the dyna-mat. You don't have to cover every square inch of the floor or roof with dyna-mat to get the sound deadening effect. It dampens all vibrations it finds in the sheet metal it is applied to so a little goes a long way. Bitt on each side of the trans tunnel and fill part of the foot wells as well as some on the fire wall. If you are using it as a heat barrier it needs a broader coverage to reflect the heat out of the cabin. A lot of people obsess with covering every square inch of metal, which is more economically done with a spray on like Lizard Skin.