Self-leveling just means that the lights will correct for issues like a heavy trunk, which would normally cause the lights to be aimed higher than intended. But those knobs let you adjust the "baseline" height.
I've seen other forum members say they think the M3's lights are aimed too low even compared to normal 3ers. Two full turns in the up direction seems to satisfy most of those people. I personally have no issue with it but there you go. Also note that the driver's side headlight is SUPPOSED to be lower than the passenger's to make it easier on oncoming traffic, so don't try to make them even; that's by design.
Last edited by jphughan; 10-20-2011 at 11:47 PM.