As I was tearing my 06 front end apart for servicing I figured I'd paint the rotors and clean the calipers, etc while I had wheels off. Came across this plug that was not plugged in at all. However it threw no codes, etc. I ended up putting it back together and ziptying it closed (the tab was broken hence why it was apart) but cannot tell anything is different and there are no codes thrown with it plugged or not plugged in as far as I can tell? the pic is of my driver side front rotor.

 

Also couple before & after pics of the rear. Calipers match the front JCW ones now and rotor is black instead of rust colored.

Before cleanup...


After paint and cleanup of exhaust & wheel area..

 

I assume you have xenons, as that looks like one of the headlight leveling sensors.

 

Ahh... yes, that looks like it. Thanks. Just did some xenon research and it appears that's what it is:

http://www.realoem.com/bmw/enUS/show...diagId=31_0623

 

Yes that for sure is the headlight level sensor