I have the "media" adapter for an iphone 4s PN B188.8.131.528.309
...but... whether this works or not depends on what set of options you have.
My dealers parts desk were great, I gave them my VIN, which they went and checked first on their list, against my options plus when I bought it the actually gave it to me to try out first before I paid for it... £144 !!!!
but I get album aret a lot better 3g connectivity for bmw live and phone, plus it keeps the phone charged to so worth having....