I can't help you with your original question unfortunately, but I was wondering, this retrofit requires coding, how are you going to have it coded. My guess is that only the dealer can code it, that said perhaps you should have the dealer do the retrofit. Quite frankly this job looks incredibly difficult given the history of BMW installation instructions leaving out steps, not to mention the numerous changes that took place to the X5 during it's production run.

If you do manage to get it all done yourself, Wow!