If you go this way and get it working let us know. I would interested in this too so I can put one in my wifes car. Cost me $3000AU to get the F900BT, reverse camera, steering controls and install but you do get free new maps in August. Would be a lot less if I bought it from the US.
I'm not convinced that the unit would fully functional in Australia that's why I haven't parted with my money. From the posts in the forums there seems to be hardware issues for traffic, FM radio. Also loading the maps seems like a pain. I personally had hoped that I could just copy a backup from my AU F900BT but this simplistic approach is probably flawed.
Good luck