Two places we used when in the area were SH5865659723, this is in a small car park, not our normal normal choice, but quiet. The second was at SH5476659818, this site is only accessible from the west unless you have a 4x4. We did exit from the east and steeeeeeply down the track at SH55665659608. I was only just able to squeeze between some of the stone gate posts. My wife walked behind some of the way to close gates etc, said I was on three wheels in places (it was very dry at the time). Its worth pointing out that I used to compete in a lot of 4x4 offroad competitions on EXTREME terrain.
Grid refs from GPS. if you want Long/Lat's let me know.
Where are you normally based?