The Nuvi has an option to connect to the FM unit...BUT you must tune to a specific set of stations, and not listen to music, just the voice commands. I used it just once....sound quality was bad.

Otherwise the Garmin Nuvi is a GREAT unit.

BTW, if you are ONLY going to use it in your BMW that already uses bluetooth, you can save a few $ if you don't get bluetooth in your GPS. I travel a lot so it is nice to have bluetooth in a rental car.

Bill