Bike lights with beam cut-off to avoid dazzling drivers? Are there any bike headlights available that have a cut-off similar to a car's low beams, designed to avoid glare for other drivers? I am using the Light in Motion Urban 400 and while it's plenty bright, it blinds oncoming drivers if aimed normally. In traffic I have to aim the hotspot very low, basically defeating the purpose of having a pricy, bright LED light. 

Are there modifications that can be done to the existing light, like blocking part of the reflector that is responsible for sending light upwards? (It's a single LED with a simple paraboloid reflector) Reading about the complexity of the design and regulations for car headlights, this seems unlikely, but I'd love to be wrong. 

Alternatively, I am looking for recommendations for a better headlight. The Specialized Flux and the older Phillips SafeRide 80 seem to fit the bill. Not sure how bright the Phillips is with 220 lumens, but it meets German regulations so surely it has a great beam shape.
I have actually dramatically improved the cutoff on my 1200 lumen dual LED (just for reference) with a sort of brim made out of aluminium plate.  On road I run it on minimum brightness (guessing about 1/4 -- 1/3 power). On pitch dark bike paths I do change the angle a little as well as turning up the brightness.  

Super-speedy sketch (go inkscape!):



The light body is about 60mm long, and the reflector is in approximately the right proportions.  I mocked it up with cardboard first, before using some 1mm plate - it's tucked away under the bars, under a front bag mount and all edge and corners are nicely rounded off.  

The mounting underneath the handlebar is another issue -- overly reflective silver-grey brake and gear cables right in front of the light if it sat on top of the bars.

It's not quite as good as it was before I tweaked the handlebar angle. On (slight) riser bars using the riser as intended I had it tipped up on the left to illuminate roadside signs (UK).  I've twisted the bars so the rise points forwards at about 45° and the aim isn't quite what I'd like.

I promised pictures:


Side view





Front view





Illumination pattern (high ambient light levels)