^^ Auto-leveling......;)

what do i need to replace? Sensor?

have you recently jacked you car up? Good chance the front sensor arm rectracted/bent/angled the wrong way.

First can you elaborate on that motion of the lights? They will normally self adjust....even on smooth roads. They dip down when accelerating and up when braking.

Like the poster stated if you recently jacked the vehicle up, the arm may have swung the wrong way when lowering it. The same goes for the rear passenger side sensor. Also check to make sure that the joints in the links actually pivot freely. The old style links looked like a sway bar link (rubber boot and grease inside) that do become dry and seized --- the new style ones are a simply plastic link with an aluminum ball/threaded stud. If all checks out you may have a sensor or something larger causing you troubles.

Listen to reckless, especially if you've had recent service.

http://www.xoutpost.com/bmw-sav-foru...eadlights.html