Welcome to Z4 mysteries, such as audio and garage remote issues. Hopefully you have a current combox. For the Bluetooth audio, it is not available standard. Iíve heard that there was an option to get Bluetooth audio enabled, but I have not found that written anywhere. I use a USB to lighting bolt cable to my iPhone 6S, and you can access most of your iTunes/Apple Music features. You can also get integration with Pandora, but you may need to replace your combox, if the previous owner or dealer did not upgrade it (it was end-of-lifeíd by BMW about two years ago). I know how you feel about having features on other models not available. The iDrive was actually newer in my 2013 than my 2015 Z4.
I have had the same issues with my garage door opener. I have gone to the BMW Ďgeniusí to get assistance, but they merely go thru the instructions with you. Iíve tried using the motor learn button, without success. Let me know if it works for you. I may go back and try again. Iíve been using a portable remote for the last year.
Good luck with the new ride! Nice color!
Sent from my iPad using Bimmerfest