Apparently you can do it yourself now: http://navigation.teleatlas.com/bmwusa
The cost is $245 and from the description they will send a USB drive with the maps, the page also asks for your VIN. This would presumably be used to create the FSC code.
2016 535d- Champagne Quartz-Venetian Beige Dakota Leather-Anthracite Trim-ZLL/ZDA/ZDB/ZCW/416/4NB/688/ZTG
2016 Range Rover HSE td6
2014 X5 xDrive 35d / 2013 535i GT / 2010 X5 xDrive 48i / 2005 X5 30i / 2003 745Li / 2001 X5 30i / 1995 525i