I have tried this with silent coat which seems to be the same product as dynamat. I used self adhesive 5mm foam backed sheet under the carpets in the foot wells and the silent coat on the door panels and the exterior panels to the foot wells in the engine bay. My aim was to eliminate the drone at 2500rpm that was quite annoying, I would say that it worked to 60% and actually makes the car sound a little better with a more defined exhaust note which I like.
One of the spin off benefits was to make the doors sound rather well made, giving them a satisfying clump when closing.I carried this out in the autumn and so cannot comment on whether the aluminium coating on the silent coat will arrest some of the excess heat coming in from the engine bay, I think it will.
One of the observations I made along the way is that not much material is needed as the door interiors take several small sheets rather than a complete coverage, this due to the restricted access . The engine bay the same and the boffins among you will know that the vibrations of a sheet of metal can be deadened by judicial placement of a relatively small amount of sound deadening product.
So in conclusion, not the most dramatic result from a few hours work but quite satisfying and in my opinion worth the effort.
Last edited by Kevcaster; 10/12/20 08:34 PM.
