I live in the Motor City. I have a local guy who runs a huge shitty old surplus warehouse full of every automotive carpet, vinyl, ABS plastic, OEM sound dampener, and seat belt strap material you would every want in any color you would ever want. I usually walk in his shop with a swatch of the material I am looking for and go hunting. I know this does not help you in Colorado. But, if you wanted to make the trip he could hook you up.
Ge0