Here's another option that is considerably less expensive and adds BT 2.0 so you can play music from your phone wirelessly if it has that feature

It's probably compatible with more phones than the BMW unit.

Kensington Liquid Aux BT

http://www.amazon.com/Kensington-Liq.../dp/B0011UIX2K

I have one but haven't gotten around to testing it yet (I've maybe driven 2k miles this year). I didn't like the remote control on the steering wheel so I have it attached to the shifter. I saw a post where someone had attached it to the door handle (not sure if it was on an X5).

It requires the aux input but that is a relatively inexpensive option and easy self-install if you don't have it yet.