Originally Posted by MooseMan
Could you explain that a little more in depth? I am not sure I am following you.
A lot of cars today offer two types of lighting. Xenon High Intensity Discharge and Halogen. All Xenon HID headlamps require the use of a projector (the bug eye like things in Cabbs' pictures) to focus the light into a pattern that is usable and safe for others. Most manufacturers who use Halogen use standard reflectors or they use projectors which are like Xenon ones, but they're slightly differently designed because the light output difference is pretty big.
Most aftermarket ellipsoid projector headlights like the ones from DEPO and the ones Cabbs bought use halogen projectors because they're cheaper to produce and because they're intended for use with halogen bulbs. A lot of people still use them for HIDs simply because it's a cheap way to get good lighting and it does indeed work. However, there still is a world of difference between using proper HID projectors that are designed for HID bulbs/ballasts and using halogen projectors with HID bulbs/ballasts.
One way to do it properly is get headlights equipped with halogen projectors and retrofit HID projectors into them. It's not too hard of a job, just takes care and patience. Never, ever, EVER put HID bulbs into a standard halogen reflector though. You'll just spew light everywhere and be a dick to other people on the road.