Your dad will need to fill out an application for "Approval to import a motor vehicle". This form is available from
www.infrastructure.gov.au The application costs AUS$50. The Australian goverment is
very restrictive on what road registerable vehicles can be imported into the country, especially if the type of vehicle is already available here (in oz). But if your dad is overseas and has purchased it he may be ok, they will confirm this by checking his passport.
There are several shipping companies based here that specialize in bringing cars and motorcycles into Australia. American Hemi Speed Centre freights from Seattle to Brisbane every 8 weeks and Seattle to Adelaide every 6 weeks (
www.hemi.com.au) Your dad can expect to pay around US$550 (+ US$150 insurance) to ship his Spyder, it will need to be crated somehow.
There is no import duty applicable to motorcycles, but he will probably have to pay GST (tax) which is 10% of the total cost (including purchase of bike)... so he's looking at maybe another US$1800 ?
His final hurdle will be getting it registered for road use. Each state has differing regulations, here if Victoria any non ADR compliant motorcycle must be signed off thru VASS (Vehicle approved signatory scheme) which is a glorified roadworthy certificate, cost maybe AUS$200 - $300.
If he is persistant and patient he will get his Spyder on the road here for about
US$5000 - $6000 less than what most Australians will pay!!!
Cheers