The BMW Xenons use a projector lens assembly that focuses the light in a specific area- and this must be below the eyes of on-coming drivers- This is why you must have levelling- if you have a couple of dead bodies in your trunk- your headlights will blind on-coming motorists-
The Japenese cars that have Xenon lights do not use projector assemblies- the lights are using a normal reflector / bulb-cover arrangement- Their light output is less that the projection housings, and less focused.
That's my story and I'm stickin to it!!