Right. Carpet that can be used to cover custom kick panels and match the interior.
If there's nothing new that is known yet (which I doubt, but bear with me), another option is a parts car with a junky carpet, or even just an old carpet from a guy that replaced his.
I gotta replace mine soon, I just noticed there's a frickin' huge red stain coming from the battery compartment. Leaked battery acid or spilled bleach or something, I have no problem holding onto it and cutting it up if/when someone wants a piece for a project like that.
I found a match at Lowes ca 2006 for the texture but not the color. Some kind of boating or outdoor carpet. I spent some time with different spray dyes until I found a decent match. They look a little off under flash photography but with natural light* they look better.
By now someone must have come up with a better match for original.
*This post not intended as an endorsement for Natural Light.
-Luke / 10270 / Superman 3 Turbo Kit