Bottle some of the air thats inbetween me and the mrs It must be the best sound deadening in the world as she never hears a word i say
Im all ears lol Dynamat is what ive used in the past to good effect you dont need to cover the whole panel though
I've bought some of this and am fitting it at the end of March when I fit out the bus http://www.noisekiller.co.uk/vw_soundproofing_products.asp
We just used really thick automotive sound deadening carpet and cut it to fit every panel and floor space. It seemed to work okay, but obviously nothing will completely cut out the road noise. It was a fantastic insulator too and did not soak up moisture as we feared. It's much cheaper than dynamat and noise killer although probably not as effective. Maybe you will have to compromise between effectiveness and cost.
Try and get some of the bitumen panels...they're around somewhere. Got to stop the panels drumming as a first step.
The bitumen pads are really cheap from panel shops. They do insulate against noise a bit but are more for stopping the resonating of panels like door skins. Dynomat is a sound proofer so that's why it's dearer. Any kind of insulation will reduce the noise. Pack the cavities of the panel with insulation that won't hold moisture. You can get high density foam flooring for the cargo floor http://www.ebay.co.uk/itm/Caravan-Awning-Tent-Interlocking-Floor-Mats-32sqft-/130295826613?pt=UK_SportingGoods_SleepingMats_Airbeds_CA&hash=item1e563c88b5#ht_3127wt_689 That's only about 10mm thick. The other high noise areas are the wheel arches, engine cover and part under the rear seat.
the sound proofer would be better but if your budget wont stretch to it then the pads will be better than nothing. use a heat gun on low or a hair dryer to warm them before fitting and get a roller, a diy wallpaper seam roller is ideal, to press them on
