I can't tell you positively about my X1 with BMW Apps because it is not delivered yet. I can see the pressure to save money, but my previous experience with both BMW and MINI is that the vehicles come with a Y cable.
If you do need to purchase a Y cable, you can get it for $72.50 from SewellParts.com, they list it as part number 61122179623 and describe it as iPod/iPhone Adapter Cable-Video/Audio adapter cable (for vehicles WITH MINI connected. Option 6FP)
http://mini.sewellparts.com/accessor...2012/4917.html