Try
http://jessestreeter.com in Japan.
There are probably only a handful of JDM Gen3s in Australia, and Satnav must've been an extremely rare and expensive option back then (even in 2008 it was still a $3000 option). And anyone who has one probably doesn't have a spare.
So unfortunately your chances of finding one locally are close to zero.
They'll even be rare in Japan by now, but Jesse (or similar Japanese Parts sourcing people/companies) will be able to help.
Get the Model Number off it if you haven't already pulled it out. Then you'll be able to contact some people in Japan, or search Yahoo Auctions in Japan. It's the main auction site over there (like Ebay). Google translate will help make the Japanese language pages legible.