The Jap satnav/tv unit is useless here... I'v been through all this as my Z is full of useless cool stuff, like the compulink buttons above the mirror and toll tag, etc...
Anyway...
The fix is to (sorry, you didnt say the year of yours, mine is an 05 so I now this works for that year),get a UK 05 X-Trail sat nav unit, you loose the TV but you can install a freeview box an hook it up to the AUX. Everyone says the screen is kack for TV/DVD playback so do you want to? For me yes but I'v not got to that yet, but the sat nav works no problem...
That said, my screen has went down, suspect a fuse but from reading, its behind the stereo so will be a day when I have time to rip out he console...
JDM''s are cool, nice one... Have fun with it...