OP, forgive some of the manners on this forum. There is a bmw ipod interface and there is a factory bluetooth option. The problem is the cost and if you want it installed by BMW, then the cost gets real ugly.
Delmarco is a HUGE help with bluetooth information if you are looking to go to the parrot system. His DIY is extremely helpful. It is found easily with a search. I decided to go with the parrot system and I am waiting for the parts to arrive. I just removed my factory ipod interface because I went with the Blitzsafe XM radio setup. There is no clear best setup. From what I hear, the factory bluetooth quality is nothing to brag about, but the cost is insane. From having the ipod interface, I can tell you the install is nice and clean. I may end up selling mine soon, but it sounds like you want new and installed by the dealer.
For the bluetooth, look up Delmarco's DIY and consider the connect2/parrot ck3000 duo.