Pictures of CD Changer IBUS Connection
 

As requested here is pictures of how I connect to the IBUS.

Please note on the first instance of this I had to bull the middle of the centre console to get access to the Multi CD Changer cables which are hidden under the console mounting bracket.

Once located and I connected my dice I placed the cables near the Cig Lighter Charger that pops out at the rear of the console. I am not sure how X3 look but this is how the 07 X3 in Australia looks.

IMG_1839 Shows the location of Cig Lighter Charger
IMG_1841 Shows Cig Lighter Charger Open
IMG_1842 Shows Cig Lighter Charger Removed ( Just give it a firm pull )
IMG_1846 Shows CD Changer Connections connected to my DICE
IMG_1845 Shows the IBUS Connection connected to the resler interface
IMG_1847 Shows the location of the cables if no DICE or Multi CD Changer they lay underneath the bracket

Hope this answers your question.