If we get to give input... (I assume it's minimal but still)
Somewhere in the inner south west would be great for me, like somewhere between Hurstville and Marickville would be really good, but up to somewhere 45 mins out from the CBD would work for me. Maybe more if the track is going to be as good as it sounds. But less selfishly, the west is pretty well catered for in terms of R/C, and so is the north, were as the only thing south is the CMC off-road track. And I know there are alot of people around with cars, 'cause I see them all the time driving in the street and in carparks. If they'd turn up to a track might be another thing, but no doubt you'd get that anywhere you set up.
I realise you'll be concentrating around Weatheril Park again, so I'm wishing in vein, but it can't hurt to sugest, can it?