The first time you go to the park, if you haven't processed your season pass already, can you just show your parking pass certificate to the guy at the toll booth, or do you have to pay and just use it the next time?
What I have read in other threads, is that you pay the parking. When you get your parking passed processed they will reimburse you for the $8.
Last year I had the parking pass on my car. I went on a weekday when the park was open and had not processed anything yet. They let me pull over to the side and processed the parking pass and put the sticker on the car. If you have Joe Cool, show them all of your info and they'll probably let you in, as long as you can show them the certificates.