It all depends if you have the CD basesd GPS , or if you have upgagrded to DVD based GPS ( which is very easy and plug and play once you have found a DVD unit °
you can find these DVD units with BMW part used part dealers , maybe its going to be a little tough down under , but you should be able to do it .
pls read in this forum the messages about upgrading your GPS .
the old one with CD is now so old maps are not updated .
The DVD ones you can buy maps from BMW dealers still . they are updating every year .
so first of all you need to identify if you have the original system or not .