I find City Navigator Austraila to have enough detail in remote areas .. if you zoom in enough (scale 700metres on mapsource - detail highest). OK it misses some bits .. but so do teh other maps here too..
You'll not find much of anything for Mongolia - as I understand it .. not many roads at all .. just do straight line navigation like a ship at sea... There you are limited to either Garmins 'world map' or smellybikers 'Wanderlust' world map ...
Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S