@Mort: I just booked for two people just to get a couple cards. According to Leo, the hotel staff won't really care about numbers since they know everyone will be breaking the rules anyway. Just make sure to actually book a room in the hotel that Summer Jam's being held in.
As for cars, that's the next thing we need to figure out.
In my car it's going to be Vince, John and Andy (Buddy of Vince and me who's coming from Saskatchewan). So there's still space for one more person in my car.