Originally Posted by Autoputzer

The "safety lobby" (Nader, Claybrook, et al) prevented modernization of headlights for years, arguing that non-standardized headlights (anything other than US sealed-beam headlights) would increase repair costs to consumers.

My 2002 BMW had the optional Xenon headlights that self-adjusted vertically. There was a sensor that measured rear suspension travel and that data was used to level the headlights. The Xenons was bright but highly focused. Pointing the car at a wall, there was a distinct horizontal line where the light mostly stopped. That didn't stop people from flashing their high-beams at me in anger, though. They'd get really pissed when I flashed mine back at them.