Anyone insulated the Fender Wells for Widebody treatment???

[AutoRnD]

I've got a FRS with a RB V1 kit, about to go V2. While we're repainting the whole car I really really want to insulate the fender wells. With my 2 kids in the back it's ridiculously noisy. I bought this car with the intention of being able to take kids in it when needed. I drove this thing from NorCal to SoCal to attend Formula D and my darn ears were ringing.

After a little google searching I found this product. Anybody ever use this?

http://www.designengineering.com/cat...boom-mat-spray



I am strongly considering cutting out all the metal, spraying this stuff inside there, then actually welding a metal tub in place of the cut out sheet metal to seal the area.

I believe most people who just assume to use expanding foam but this is just a recipe for rust and mold/mildew. Neither of which we want considering these areas are practically unreachable. It's a quick way to kill a car.

our car

[AutoRnD]

If you know of any other similar products that are sealants, prevent rust, don't absorb moisture, and are sprayable please please post them up here.

I intend to take photos of the progress we make on building a quieter FRS, lolz.