Carpet underlay/sound deadening?

[nelson84]

I am replacing the carpet in my 85 vette. In the back hatch area there is some carpet underlay, should I just put the new carpet over the old, or should I replace it? Or just rip it out and put carpet in?

 

[CharlesBrown]

This is a prime opportunity to guard against resonance and other unwanted external noise. I'd get some sound deadening material (see MAM catalogue) and put that down first. The good stuff is quite thin and should not cause any problems under the carpet.

 

[Sunstroked]

The underlayment is the factorys poor attempt at a sound deadener/insulator. If its in good shape, doesnt smell, etc and you're on a budget, I'd leave it in place. When I order my carpet in the very near future, I'll be using a product such as dynaliner made by dynamat. Supposedly it is a far superior product to what the factory used.

 

[nelson84]

When I reinstall the underlay I will use a spray adhesive to glue it down. My question is do you glue the carpet to the underlay as well or is the carpet fastened down with screws or something? I guess it is held down in some areas by the seats and seat belts and the storage bin doors. Should I glue it down also?

At the back of the hatch area, on the vertical part, do you glue it or does it stay there on its own.

I guess if I glue it down, how do I run wires for a new stereo?