Hi,
My brother and I traveled the Border Track from Pinnaroo to Bordertown a couple of years ago - camping at Pine Hut and Red Bluff. Our Subaru Foresters had no great trouble, even though some tracks had become quite scalloped. We did, however, bypass the largest dunes after coming across a couple of larger vehicles who had turned back. Being Easter, there was quite a few vehicles on the track.
Not sure if my reply will be too late for you - would be great to hear how you went.
Dan