I also think BP on opposite side of road probably not best option.
I think you will find that getting a carpark for 15+ cars at the BP will be more of a challenge than Dreamworld, especially if we are meeting at 9am.
I vote pick a corner of the DW carpark furthest from the entry, and we will vacate the spots before 10am when DW opens. People are too lazy to park further away than they have to, so we will be in the spots left till the very last people arrive anyway.
I think Tambo will be a real squeeze for us all. If there is no lawn bowls on, suggest the side street up next to the Shell servo, at least we can park both sides of the road, and people can wander to IGA or the loo if required. You could of course park the other end of town, outside the police station