Registered to drive around in the grounds YES. Drive the Heath Cruise NO.
If you pre-registered, you would have gotten a car pass and 2 people passes.
I didn't pre-reg, so I have to pay for 1 Car pass which comes with 1 people pass (driver), I think $80, each additional weekend pass $40.
If you want to drive in with food, drinks, stuff, etc. You have to be in a Mopar or AMC, and register it.
If you want to save cash, you can park outside and pay for a $20 day pass, $30 for a 2 day pass or $40 for a weekend pass. But you are stuck paying for drinks and eats.
If anything, have some chairs for the tent and later for the cruise.