I suspect the gasket you're talking about is the one that unions the inner wall to the metal frame and is visible when the door is closed.
Mine are just pressed on as well. When I got my PC 5 years ago it was used, 2010 model, and I thought the passenger gasket was too long too. However, after investigating a bit, I found that it wasn't pressed into to the curves and corners well.
I noted where it started/stopped. Took it completely off. Cleaned it and wiped it with Armor All. Then I started pressing it back in place making sure to get it into the corners well. I started at the same place and inched my way all around the opening. Surprisingly it was the correct length now. The door also closes easier and rides quieter.
Larry