Sorry guys I don't really know what it's called. I've seen it in the carpeting department of my local HD.

 

I just bought a roll of "Temporary Carpet Protection" at a home improvement store. It has a low-tack adhesive on one side, and I plan on putting it over the carpet in my S2000. I've seen this stuff used in homes being sold as runners, which prevents people from tracking up a clean carpet. It's pretty thin, and probably won't last very long but it is inexpensive and disposable, so it will probably save some wear-and-tear on the carpet.

 

update:

i went into advance auto parts and bought clear floor mats for like 10 bucks. they work and look very good, it is exactly what i wanted. so now i can still see the tan carpeting but with the extra protection.