For some reason best know to themselves Porsche omitted a rear splash guard on the passenger side so all the road debris finds is blasted into that area, and the rubber gasket around the gas filler nozzle is right in the way !! Mine was completely shredded so when you went to fill up with Gas the cap was covered in road grime etc ... plus this also increases the chances of getting debris in the gas tank.
Removing the old one was fairly easy, except the drain tube is attached with a clamp and was a fairly snug fit after all these years.