[Christ]

Originally Posted by Cd

I agree. My 'pan is aluminum and I was surprised at how heavy it turned out ( several pounds versus a pound or two for Coroplast )
If you use thinner aluminum, you will also get rattling anytime you are stopped and the car is at idle.)

Unless you dimple or crimp the sheet. That's why the body floor of your car has "designs" in it. It adds to the rigidity of the metal against reverberation due to vibration, and makes it more structurally stiff, as well.

If you just add a couple bead-rolls into the sheet metal, the vibration stops.