My car has the 725 Midnight Green deluxe interior and the original factory dark green mats, and the passenger side mat has "P.P.I. 4320R-1" and "3949520" molded on the back side, near the rear edge; the driver's side mat has the same numbers, except it has "L-1" instead of "R-1". The numbers were in the mold, so all colors should have the same numbers on the mats, but the sets boxed by colors sold over the counter would have different part numbers on the box.