Hi there, the only real experiance of sound deadening was trying to restrain over 140db in my old polo. (ah my formative years lol )
Bearing in mind that I ended up with 1/2" thinkness around most of the boot I needed somthing a little cheaper than the commercial products. I found that If you go to your building supplier they probably sell a roll of "aluminium backed bitumen" the ally is pressed in squares. its used in flat roofing.
If you warm the back of the pannel with a heat gun and then apply the sheet (also slightly warmed), then heat the whole lot in situ (it should stick to the warmed pannel), then press it in place (with gloves on)
I found this to be very satisfactory exept for the weight added but this was a large application, ill try and dig some pics out in a bit but the only one ive got online at the mo is this one
