Hey buddy, sure there will be plenty here keen for a cruise.
My only concern would be to say that that carpark (in Campbelltown) isn't very big, and its noramlly full of tourist taking a piss at the best of times. You've got the potential with all area invited to have heaps of cars there so maybe you should look at a bigger meeting area.
My suggestion would be to ring the Campbelltown council and see if they have any objections to having the meet up at the footy oval a couple of hundred metres north. Probably won't care but might pay to ask. Only other issue with that is weather there would be a local footy game on, but council could probably tell you that too. :)
Cheers,
Si.