That doesn't look like the factory one to me. The option code is B48. Why I dont think its factory. I cant see it but there should be material glued to the inside of the hinge mounts. There should be a non-molded piece that is glued to the rear body panel to cover up the taillamp mounting nuts. That panel sits over the edge of the main floor mat and covers the edges. The main floor mat part was molded and should have a slick back to it. Like its covered in clear vinyl, sort of.
Edit: Find a pic of a eBay GNX auction. The B48 option was standard on a GNX. There are always plenty of pics of those auction listings.