Since you know the Country/State/City/Street of any saved destination (just by calling it up) - why not find the same location in Google Earth and lookup the approximate GPS coordinates using the Lat/Long grid feature? Once you have the approximate coordinates, you can always fine tune them by comparing the DESTINATION map that displays in your BMW Nav display with a special Mapquest map which uses the Lat/Long you got from Google Earth (http://atlas.mapquest.com/maps/latlong.adp). It's a little cumbersome but it would work.

The other more obvious tip is just DRIVE to the destination in question and use the EMERGENCY feature on your BMW Nav display to show the current Lat/Long position.

Good luck!