I just ran a search for this, and I couldn't find anything. I am looking to try to find out what kind of insulation is used on the underside of my hood. I'd really like to try to add some insulation on the underside of the hood, maybe in the fender wells, and perhaps at the firewall between the engine bay and the cabin. Does anybody have any suggestions as to what type of insualtion I could use for this? Or an answer to the first question which is what type of insulation is factory that comes on the underside of the hood? Any help would be great, thanks.