X5 2002 Nav System Installation

I own an 02 x5 and has the standard in dash cd player stereo with a 6 cd changer on the back. I want to install the 16:9 widescreen and the MKIV nav computer but the dealership wont do it. Do you know who can do this and where? I saw the equipment on bimmernav.com but there is no info on the web page and theres no way for me to ask them who can install it.

thanks