Hey dj,
Here are a couple recent threads, but unforunately they don't give 100% of details. I previously searched back several months & couldn't find anymore detail than what's in these threads. If I find more, I'll add em here for you.
http://www.xoutpost.com/x5-e53-forum/...ighlight=Angel
http://www.xoutpost.com/x5-e53-forum/...ighlight=Angel

It might be the wisest to just link them to the Fog light wiring for now, which saves you from digging into the tucked-away ECU, as well as having to lengthen the wiring to reach there. If/When you have another reason to get into the ECU, you could rewire them then to be always on or wired to switch, etc. That seems to be the consensus recently. I was hoping to have mine installed by now, but it shouldn't be long...