Sorry to rattle on about my sound-proofing (no pun intended);

Had the dynamat put over the whole floor yesterday and up the firewall as far as paractical. Here is my report.

SUMMARY: I would recommend this to anyone who is irritated by road-noise, perhaps has just rubber mats over bare metal at the moment, and wants a quieter driving environment for long road-trips. MUST have a solid floor that will not need work in the next few years or it's not worth it.


I am very pleased with the result overall, considering this is just the floor (no stuff on the doors, roof or hood).

There is a significant reduction to road-surface noise - you don't get that change in tyre-roar when you go on a particular kind of motorway surface (in UK they seems to be sandy-coloured).
The clonks from underneath (axle etc) are also much less noticeable.
Transmission noise is much reduced, with the added benefit that the heat from the tunnel will not get through into the car as much.
You can hear the radio much better at 50-60mph.
Noise reduction at 70-80mph is less easy to determine but I am sure that road-noise at least is significantly reduced.

The stuff is non-porous and creates an almost inpenetrable seal with the floor, so leaks should not cause worse problems. However, if the floor needs welding in the future it will be more time-consuming to hack off the dynamat.

Total cost: $100 for the materials +labour (2-4 hours)