Wardl
I am in the opposite boat. I know if you can show ownership of your car for over a year you can take it in to Australia as a personal import but you would need to convert it to RH drive which can be done depends how much skill you have. The rest of the issues are straight forward if you work thorugh a good engineer. Once you get it there (will your company pay the freight) you will find the superformance is worth more in Australia than the US so it is worth taking it over then you sell it before you leave and buy another one when you get back to the US.
Maybe we swap my Harrison in Australia with your Superformance in US.
Cheers
Bruce