I don't think BMW provides DVD map updates for free. If you want an updated map, you have to get it from the BMW dealership, NAV-TECH does not sell map updates for BMW on their site.
Also I experimented with copying my DVD, and it works, but unreliably. I did an "exact copy" data disk with Record Now DX on a DVD+R.
My idea was if it worked, to go in with some other owners on an update, then burn copies for all.
With the burned disk in there, this is what happened:
Sometimes, about 1 in 20 times, the nav computer does not start up. The splash screen never appears (------BMW-------). If I shut the car off and let the system reset (~3-5 mins) it comes up fine.
Other than that it works perfectly. I have since put the original back in and it hasn't had the failure again, nor did it ever fail before I put the copy in.
So.......I am thinking of burning another as I have a newer version of Record Now DX and see what happens.....