Excellent post and the additional details beyond the instructions really made this possible for me. I do have to respectfully add one correction though. Now, I could be wrong and my car may be different but in step 7 where the white BMW connector is shown, the black and black/grey wires in pin 1 and 2 are actually the large ones to the left (wires are not shown on the original picture), not where it is circled in red in the original diy picture. I've attached the correct location circled in blue. The incorrect location is circled in red in my picture.
http://i61.photobucket.com/albums/h5...psb0cumxxc.jpg
original picture, it's not the wires circled in red:
http://i61.photobucket.com/albums/h5...psahgmkeig.jpg