Halogen does not come with self leveling in US spec. vehicles. The retro for that involves a lot of time (dealer or otherwise) and a BMW kit. NOT CHEAP!
I'm working on my own "self leveler" circuit. I already have a manual one I built to adjust the dip (via the stepper motors) without adjusting the high beam. Now all I need to do is find time and patience to write the program for a PIC.