I just went out and checked my new cap and it has a green gasket. It is snug on the rim where as the old one was always a little sloppy. The dealer had one in stock which surprised me but I was told they always have one on hand in case one fails the emissions test.
I will be getting the GMPP in a few weeks and it will be covered for 3 more years, I checked. Another hodgepodge set up.
