Thanks for the suggestions all! We do plan on renting a car, so that will make access much easier. Is it worth taking a leisurely drive to Melbourne from Sydney (maybe stopping at beach towns along the way), and then taking a one-way flight back? Or is it kind of a bland drive? Perhaps that time would be better spent in the cities?

Also are there any "unusual sites" along the way that may be worth checking out? We love things that are out-of-the-norm.