I bought:
http://www.amazon.com/gp/aw/d/B004E5...sr=8-1&pi=SL75
And
http://m.bestbuy.com/m/e/product/det...=1218803450090
And iPhone 5 plays music through the iDrive. The BMW adapter feeds through the center console and the cable gives a few more inches of cable to the phone so it's easy to plug in without opening up center console or anything.
/thread