Hey guys, I'm finishing up tidying my trap door section and trying to get rid of any rattles on my 69 Mach 1. I see some videos and pictures online where there is actual carpet that extend pass the trap door and into the trunk. Mine do not have that. Where is this carpet coming from? Is this factory or something people add just to get rid of any rattle and seal the trap door better? An example is in the picture below. Thanks!