I replied to you on roadfly, but I will try again here...

I did my aux input install yesterday on my 05 X3 with nav and dsp. Did yours come with installation instructions?

What concerns me about giving advice is that my black 12 pin connector only had two wires going into it and yours had four...

Moving-on from that, did you put the wires from the aux input into the existing 12-pin harness, or did you switch the entire harness leaving the old one unplugged? That would be the first place to start.