this is what I used, it is about half price on sale
https://www.princessauto.com/en/48-i...t/PA0008681660
the spec says .31 inch thick. Whatever the thickness is it is thick enough to feel like it has some substance, but just thin enough to more or less conform to the straight edges of my tunnel....about the same as you'd expect carpet to drape over something
I'd be surprised if you can't find something similar at home depot or some similar place