yup, I also have an eject box pre-installed but the connector is not compatible with the new iphone snap in adapters available with BMW NZ. If your eject box looks like attached pic, I will be interested. The idea is to remove the current eject box (designed for BMW Motorola Phone) and change to the universal one, then add a iPhone snap in adapter.
Your car may have the steering controls but does it have the bluetooth unit installed? it should be a box in the left side of the boot behind the liner trim. If you don't see a box and don't see any wiring connectors as per attached pic, it would mean that your vehicle is not prewired for B/T unit.