You could provide just a tad more info in your question. Are you trying to listen to audio through your speakers, do you want playlist information to display, do you want to show video on the nav screen or rear seat screens, do you already have an aux input, do you want to use bluetooth with charging docking cradle and functionality through additional OE BMW bumper mounted antennas, etc? It wouldn't kill you to do a search either as the question of using an ipod in an X5 I would think, and this is total guess, has been asked before. In addition, E53 X5 tips and tricks page has probably a dozen mentions of 'ipod.' As it stands your question basically says, "I need a car, any advice?"