Be pointless to just drive across the nullabor IMHO.

You really wanna take it easy and see as much of the south coast as possible. Head down past esperance, cape arid etc, then towards toolina cove and play around on the old telegraph lines.

im sure theres stuff to do in SA and could hit great ocean road and see the 12 apostles etc. Sure it would take a few more weeks but damn it would make for a memorable road trip with the boys!