I dunno, something thick, heavy, and inert should do the job ( a couple of students would probably fulfill that criteria.....sorry just come off the General Thread about students :twisted: )
To be honest, it would need to be pretty dense and heavy to dampen the resonance that normaly causes the vibrations. I thought about foam rubber but it probably isnt dense enough to stop the resonance. It would need to be pretty flexible too so that it can be moulded into shapes and corners.
Will have to have a look round some of the larger DIY stores as there might be something similar that could work as well.
I have heard that you can get some of this stuff from a builder merchant ( Platform) The sell a large roll (more than you will need) for a fraction of the price. You cut it to fit, and heat with a blow torch. Will try to find out name. Will be giving it ago myself at some point.
most people use flashing tape,as its the same sort of stuff as dynmayt only thinner ,most peeps use multiple layers on thier doors and boots,screwfix is the cheapest place to get it,you can also buy a proper sound deadner from another site but i not sure if i allowed to put links up ,if i can let me know and i will,lol
go to a bodyshop and get some sound deadening pads from there.....there are about 9"x18" and only a few £.....
thats what ive used..... :wink:
as for in the boot....ive used expanding foam ..put over the wheel arch area....
I think you will find that polystyrene (I am guessing you mean the stuff like celing panels) and fibreglass loft insulation are fine for insulating against temperature, but wont be too god at sound deadening. You need something quite heavy/dense to stop the resonance and vibrations which neither of these are.