I did an HID conversion on an old set of CEBEI lights a long time ago. Had H1 bulbs in it and had to make new holders to hold the HID in the right place. To make the optics work you need to put the kernal of light of the HID in the same spot as the filimit of the old bulb. A little rework to the back of the housing to hold the ignitor. I had myself a dirt cheap set of HID off-road lights. Optics were still jacked, but in a good way. The main beam was a bit of a bowtie pattern, and the had massive overall glare. So they did a pretty good job of lighting ahead of you and quite a bit of all around as well. Walls, tops of trees, side trails, fence lines. Absolutly could not use if anybody was in front of you, they were totally blinding. Probably lacked some UV filtering as well. A proper lighting engineer would cringe at the results. Completely unsuitable for street use even in daylight.