Most door seals are cut too short. In the video here, you can see why and the proper way to terminate your door seal.
Chopped door gaskets fray and make the car look shabby. The factory had this figured out, and terminated the seals under the dash in front and under the rear panel in back. We sell a kit with a seal long enough to terminate under the dashboard and behind the seats, as shown in the pictures here. You can order the kit by clicking here. And you can see still pictures of the proper ends in the pictures below.