Because I see more an more those kits on public roads (blinding me), I decided to post here some links that will offer more insight in the illegality of those kits and specifically explain why no matter of 'adjustment' will eliminate the glare or make them illuminate the correct field - they usually throw more light in front of car but they miss the sides, making actually less safe to drive that vehicle.
The whole issues starts from the fact that filament and HID arc are different dimensional and photometric. Basically a housing designed for filament cannot take the bigger HID and focus it properly.
Read more here:
Daniel Stern Lighting Consultancy and Supply
United States Department of Transportation's letters/statements :
http://dsl.torque.net/images/techdocs/NHTSA_Crackdown.jpg
http://isearch.nhtsa.gov/files/deetz.ztv.html
http://isearch.nhtsa.gov/files/Shih.3.html
http://isearch.nhtsa.gov/files/kim.ztv.html
The whole issues starts from the fact that filament and HID arc are different dimensional and photometric. Basically a housing designed for filament cannot take the bigger HID and focus it properly.
Read more here:
Daniel Stern Lighting Consultancy and Supply

United States Department of Transportation's letters/statements :
http://dsl.torque.net/images/techdocs/NHTSA_Crackdown.jpg
http://isearch.nhtsa.gov/files/deetz.ztv.html
http://isearch.nhtsa.gov/files/Shih.3.html
http://isearch.nhtsa.gov/files/kim.ztv.html