Sounds like a good idea.
There was a Canberra/Sydney cruise about 12-18 months ago, went through Kangaroo Valley and stopped at a dam somewhere.
And that was a big sucess A very good day. I think there was about 40 or so cars !!
It's all in the planning. Plan times, route, meeting places, desination, and a fail safe just incase a few people get lost
J