There are some Draconian laws to be observed.
Attached you will find a link to Government website that sets out some of the requirements.
Basically the car has to be manufactured pre January 1989 to be imported unless it is a "private" import(post 1989) for which the car has to be owned overseas for 12 months, plus the importer has to live overseas for the same 12 month period( and believe me they check!!).
Then on top of that, the car has to comply with Australian design rules applicable at the time of manufacture.
Its all about "protecting" the local manufacturers(read GM, Ford Toyota!!!!!!)
But apart from that, an importation can be a viable option, especially with the value of the Aussie $$ at present.
Search "carsales.com.au" plus Morgan Owners Club of Australia to see what local prices are.