To the best of my knowledge, having done this once a few years ago. Rules are, you must convert to RHD unless the car is 30+ yr old.
The other advantage is the reciept of a private import plate for the equivalent of a roadworthy inspection.
When I registered the car I imported, I didn't even need to take it to the Rego station, just the paperwork. That can be an advantage on 'unusual' vehicles.
And of course in today's market, prices are very attractive.
Buy a Superformance with low miles in the USA - middle to high 30's US$, at our rates, under 50K Aussie. Bring it in, pay the 15% duty. Put it on the road, even with stamp duty and rego. You would have a great car on the road for less than buying a local roller
Or buy a Kirham or Shelby for that matter!!
Cameron