We have the option in my state to register for 3,6 or 12 months at a time. Provided the vehicle is not unregistered for more than 12 months continuous another roadworthy inspection is not required. Once the vehicle is 30 years old it is eligible for historic rego which is very cheap but has some restrictions on when you can ride it and requirement to keep a log book. Some don't take up this offer if they ride alot. I will because I don't do many road kays.
sorry just saw this. We too in melb can register for 3,6, or 12 months. But am i missing something here. If u register it for 6 months..... then after that u have to go through the whole roadworthy process again