I've had to do a fair bit of reading up. It's straightforward-ish but you need to make sure you read up on the requirements. You can't just buy a car and take it over, you have to be moving to Aussie with the intent to live there, you have to have owned and used the car for at least one year ect.
The duties also make it very expensive. For my car, depending on how they value it, I'm looking at around 15-20k all up. Sounds crazy high, however the cars are also more expensive there. If I take that into account, plus the fact that I might not get a good price trying to sell it here, the fact that buying an unknown used car is a risk and I might have trouble finding my ideal spec at a good price... it still doesn't seem like a totally stupid idea to ship it
Their import laws do indeed make bugger-all sense now that they have no local car production. And some job it did at saving their car industry lol. But they seem to love their duties and taxes, as well as all kinds of laws and fines a hell of a lot more than Kiwis!