See in the V series skylines section in the forum, this is being covered a million times
basically, you can not RE-Program it to work with Aus Maps, but Australian NAV can be retro fitted and made to appear OEM via the original screen,
also there is fix on the way for Menu to be in English... its running behind schedule 15 months, but coming.....
Guy called Chris Rogers in Brisbane who fixes DVD (to play DVD and MP3), Fixes Aus complaint TV Tuner, Radio Fix and iPOd control as well.....and Nav retro fit....
but heaps of infor on V forum........
is your sedan CVT-8, in that case don't search by that "keyword"as you might go in to depression