Hi Hollywood,
That's encouraging news!
From whom did you purchase your unit? The Eonon NJ distributor or from them in China direct from their web site?
Yes, that special cable makes connection to the existing radio tuner under the rear floor area, just forward of the battery.
I have bookmarked this as my guide for when I tackle this project
http://www.xoutpost.com/bmw-sav-foru...placement.html
This is the place in the rear where the special cable connects for factory nav vehicles
http://i285.photobucket.com/albums/l...IMG_0564-1.jpg
http://i285.photobucket.com/albums/l...IMG_0583-1.jpg
The Eonon unit to my knowledge does not work with DSP equipped vehicles.
Mike