Wife's X5 had Nav, CD changer and amp on the left side access panel of the cargo area. If you had DSP it would show up on the menu of the display screen of your old Nav unit. From what I understand, if you do not have the subwoofer on the right side access panel in the cargo area, you do not have DSP. As to the LED back lighting, I noticed the short harness that comes with the unit has a pink wire on it labeled illumination. I don't think this wire is there on the extended harness judging from a photo I saw on the ebay web page where I originally purchased the unit. I haven't verified this as I'm waiting on a couple more things to arrive before I tear into again. If this is the problem I will take some pics and post them.