Current import calculations for bringing cars into Oz are...
If vehicle is less than 30 years old = 5% DUTY + 10% GST + Luxury car Tax (LCT) calculated at 33% for every dollar over AUD $ 57,180
If the vehicle is over 30 years old NO DUTY is applicable , however 10% GST and LCT calculated at 33% for every dollar over AUD $ 57,180
If a race vehicle Duty is calculated at 5% + 10% GST
SpookyPT