What's the technical term for the black goop that car manufacturers cover the interior floors with and which racers chisel/melt/freeze off to lighten their car? And let's say you removed some of it on a daily driver to nip a little rust in the bud and now needed to replace it: whose goop would you buy if you wanted to do the job right?
Sound deadening material. I hate the OEM stuff with a passion.
http://www.secondskinaudio.com/
I've never heard of a single issue with their products.
If you want to go cheap, and possibly smelly, you can get peel and stick roof sheeting at your lowes-depot. I've seen that stuff soak through carpets, but it's cheap and very easy to obtain.
We call them "melt sheets". Basically melted asphalt in the floor of the car.
"Jute" is what I've heard the OEM stuff referred as. Unless you're going for 1000% accuracy in a restoration you're better off without it.
Jute is the fibrous padding under the carpet.
http://www.stockinteriors.com/jute.asp?ItemId=4794
No affiliation, just the first Google result.