Found this on the other forum Im a member of, its for a 2006 M3 :
hey guys, i finally installed an auxulary input in my m3...
firstly i purchased the aux input for this..
got it from bmw cost $160 AUD.
then buy this for your ipod http://www.europeanautosource.com/pr...roducts_id=885
the good thing about this connector is you can use your disc selector numbers to make the volume higher or lower.
DO NOT USE normal headphone outlet jack because quality is shithouse.
then with allot of trouble removing the dash and the monitor.. you will find a spare "male type connecter" for your aux cable you purchased from bmw.
connect it and run it thru your glovebox..theres a spare hole just above the space in the glovebox you can run the cable thru..
i love this cable.. i was told by bmw that you cant use the stacker once this is installed but its bullshit. now when i press the mode button.. i get 4 options. Radio, normal monitor cd player, stacker and AUX..
i dont know why bmw dont know anything about this.. i ask nealy every single bmw tech they all said u cant use your stacker with the aux input..