Just wondering if you could use rubber sheets? I've got some 4mm thick rubber mats that I use for making gaskets and washers etc - could I bond this on and would it work?
It would work diddy as its raising the density of the panels Im going to spray stonechip protection on the inside of panels etc to achieve them same result
the rubber mats are surprisingly heavy as I already have them and it will cost nothing it might be worth a go I suppose I do like the look of the foil/lead backed stuff in Birdys post though
I used this in my door panels for vibration http://www.diy.com/nav/build/building-materials/roofing/flashing_tapes/Evo-Stik-Flashband-Grey-3-75m-x-100mm-10517614 Just cut some strips and stuck it to the inside of the doors/body panels. And this http://www.homebase.co.uk/webapp/wcs/stores/servlet/ProductDisplay?langId=110&storeId=10151&partNumber=127033 Which is waterproof to add a bit of insulation. (I also used it to make some cheap window insulation which seemed to work at Winter Camp) When reading on the subject Celotex seems to be best for insulating panels. Did the job cheaply, seems quieter and the doors now close with a thud.