Assuming that the FOB price is 2,000,000 Yen ($24,000AUD), then the GST would be: $2,400AUD; and the stamp duty would be: $2,746AUD.
Then you have customs and clearance fees wich will be approx: $6-700AUD
Shipping costs are usually $1,000-1300AUD (for roll-on, roll-off) depending upon who you go through. If you decide to use a container then the price is doubled.
Add to that steam cleaning which can be anywhere from $60-$242AUD depending on which port the car is delivered at.
Then you might have to include twoing fees, and depending upon what car it is, compliance costs range from $3-6K.