Well you will have to pair your car with your phone. Please refer to you car manual. Then you just connect to the car bluetooth system with your phone (some systems might auto connect) and the system should be enables as an bluetooth audio gateway. After that you are ready to start playing music from the media player. Though if you car bluetooth does not support a2dp the sound quality could be terrible. Atleast some old bt systerms were for hands free only therefore they did not support proper bt audio profiles.