I went to all these areas in vitz 05 and no problems at all, the hotel we stayed in muree has the worst gradient and cars with cng or less power do not go up there but my vitz climbed the height without any issues.
Just note that B and S gear selections are for downhill controlled speed but do not keep these options selected for a longer duration. Like after a minute or so change selection or your gear system will heat up or may get damaged, refer to owner manual for further details