iPhone Integration Question

Hi everyone. I've owned a number of BMWs, and in the last month have purchased a 2012 528i (wife's) and just today a CPO 2009 750li (mine). We previously had 2006 models, so the integrated iPhone was a welcome addition for our cars.

Everything works great on the 528i, but when I plug in my phone through the USB port on the 750li it says "Reading" for about 1 second and then "Not Supported". I can use the aux port, but thats not what I'm really looking for.

My car does have the 06NF Smartphone integration. I've tried two different cables, so I don't think that is the problem.

I've done a bunch of searching and found a few different answers, but most of the info I've received doesn't come from the 7 series. It looks like the right thing to do is:

1) Get a $355 special cable from the BMW dealership
2) Get the snap in adapter for around $225
3) Get a Y-Cable from Amazon for $25

Could someone tell me which is the right answer for my car before I go purchase something I don't need?

2009 should come with the y cable

If it is a cpo they will give it to you

Ok great - they didn't give it to me and the dealership is far away so I can order one from Amazon easy enough. Thanks!