Before I do wiring I decided I better apply the noise damping material because I won't be able to put it in after wires are run. This is special material for damping. Damping means reducing vibration. this is not a noise abosrber. this is a noise preventer. Later I'll put some foam for noise absorbtion. This material is 1/8" think with a stick back and aluminum on one side. You stck it to large open areas of aluminum skin where they might vibrate.
Since the muffler will be spitting out noise under the cabin, the first place I'm putting it is under foot. It is kind of expensive. This one piece was about $125. I stuck it down to the whole floor under the forward cabin.