It looks like the GPS system is shared across all models of BMW's line:
http://www.1addicts.com/forums/showthread.php?t=700662
In last place of all GPS systems compared - that is so sad. BMW, I hope you lurk these forums and get this addressed as soon as possible.
Audi was smart to outsource to Google Maps rather than attempting to squander precious R&D dollars on useless products in the end.