Purchasing an older vehicle is a viable option to renting one, thanks to websites like Cars 4 Backbackers/Travellers Auto Barn which provide a useful service for travellers wishing to take up this travel option. Travellers can purchase a cheap car, campervan, station wagon and 4wd through the website, and when they have finished with it when they are ready to leave Australia, they simply advertise it on the website and sell it to another traveller seeking their own set of wheels during this visit to Australia.
Using the search engine (right), check out what vehicles are available. If you like what you see, you can put down a deposit, securing that vehicle for the day you arrive. You can buy vehicles from an unlimited number of private sellers who can list for free, or from Travellers Auto Barn, which has sold over 30,000 vehicles to backpackers since 1993. 
All vehicles bought through Travellers Auto Barn come with 3 day money back guarantee, 5000km engine/ gear box warranty and a guaranteed buyback from six Australia wide locations. All campervans and wagons come with the ability to sleep in the vehicle ... meaning big savings on your accommodation budget.
Check out what vehicles are available at the time you want to travel by using the search engine on this page.