Need to add blue tooth music to 2014 Audi Q5

Same issue with an 2011 A5. These are my kids cars and they love them but they want their phone, really their music from their phone to be able to play though the car. Preferably though Blue tooth. They have some crazy mmi setup or something. You can make calls etc hands free but not play music. It’s a weird system, we are used to just phones connecting automatically via Bluetooth.

Also need recommendations on installing a back up camera system. She has the screen but navigation package. I got car at auction unexpectedly so I am not complaining