As many people have commented on here the Octavia does suffer with a lot of road noise. So I found on ebay, from a car audio specialist some of this "SoundX Car Audio Sound Proofing Noise Deadening 8 SqFt" for £16 .

It arrived this morning and was amazed that what turned up was actually a bitumen based flashing tape called flashband that i use daily in my job as a window Installer, i have in the past lined the doors of a previous car with it . It can be had from your local merchants for £7 for 10 meters

So i shall be trying it out in the boot of my car and will post the results.

Sounds interesting. My estate is a real boom box and not because of the stereo (constant boomy road noise). A bit of sound deadening would really improve the comfort of the car on long journeys.

Let us know how you get on and where you put the material.

Cheers,

iep

You need the material you describe (or sticky-back lead/bitumen tape) to add weight to panels that boom at low frequencies. For higher frequencies, such as tyre noise, you need thick felt (~2") and also make sure there are no gaps to the outside world.

By a combination of both (plus acoustic foam and bends) I once make an airduct to a building's special quiet room totally silent from fan noise and noise from the outside where the air came in

Try tapping the car's panels to find where to put the lead/bitumen. Sometimes you need only to put it in the centre of a panel to lower its resonant frequency sufficiently. Most cars already have a very thin lightweight combination damper material on doors and quarter panels.

Acoustic tape has more lead than flashing tape but you can double up on the thickness to achieve the same weight.