Yea to change the registration into your name 名義変換, you need a parking permit 車庫証明. This is applied for at the cop shop. Head there first and get the paperwork, go get yourself some parking and then fill out the paperwork. You have to draw some pretty pictures of what the parking space looks like and where your car will fit and get the owner of the parking space to sign it.
Personal import:
Own the car for a year. Keep all the paperwork - tax forms, shaken forms, purchase records, change of rego papers, as these are all needed when you fill out the paperwork for import approval, which can be found at the DOTARS website. When applying for import approval, don't worry too much about getting all the Japanese paperwork professionally translated, I just did it myself. Don't worry if you are not coming back with your car, just lie that you are. You can apply before the year is up, as long as it is not imported before the year is up. Organise yourself some shipping. Take your car to the shipping company yards, take off the plates and walk to the nearest train station as you now have no car. Deregister the car 廃車 and apply for approval for export 抹消, this is done at the local (how do you say Department of Transport in Japanese again?? 陸上なんとかなんとか....., when I remember I'll post up again). Send the deregistration, export approval paperwork to the shipping company. Pick up your car in Aus. Pay import duty, shipping, quarantine, etc, etc, etc..... and be happy. Get it complied and be happy.
You will need your registered hanko 印鑑 and a hanko registration paper 印鑑登録証明 everytime you fill out any official paperwork. Head to your local 市役所 and get yourself registered baby if you aren't already.
Do it all in your name as your missus ain't an Aussie so personal imports won't work for her.
My fingers are sore