Just got a 2016 BMW 750i xdrive M Sport. Wow.
Did not come with Apple Car Play. From the forums, I believe it came later.
Found Bimmer Tech and checked via VIN that my car had the feature but was not activated.
Went to the site below, paid the activation fee and got a file download. I have activated Car Play. Now I can switch back and forth between it and iDrive.
https://www.bimmer-tech.net/bmw-idrive-coding/