Hey Guys

I have looking all over the internet and I can't seem to find the answer anywhere.

I have a 2008 CLS W219 with a factory fitted Command NTG 2.5 with an aux connector in the glove box. I would like to fit a UCI kit to the Command to allow me to use the steering controls when playing music from my iPhone. I think I have found the correct part on eBay but I have not idea if it is right and also what cables I would need. Also I don't know where the main part (the big metal thing) is supposed to fit into the car. Does anybody have a fitting guide and part numbers for this or know anybody who has does this. My research also advised that I most likely will have to get the Command reprogrammed to show the UCI option in the audio tab on the Command. Is this right?

If you need any more information then please let me know.

Thanks.