If you have 2 drivers its easy. I have not done syd to adelaide, but my father and i have gone from syd to melbourne and back, straight (towing another car on the way back) several times. We have also done sydney to logan (QLD) and back (again towing cars), and 2 weeks ago we picked up a p38 on a car trailer from Moe in vic, and drove straight home.
Towards the end, if you need to sleep, just have one. Even if there is an hour to go, you can still pull over and get 1/2 an hour of shut eye and be refreshed. Another trick is to get a 6 pack of V energy drinks, they taste like manure, but they do their job (you do end up stopping every hour after that for a slash).
Andy

