When you say convert a reflector assembly from halogen to HID, your saying to put a reflector in your housing that is designed for an HID?

What i recommended really depends on far someone wants to take their lighting upgrade and how much they want to spend. The simplest cheapest upgrade would be using a better halogen bulb. If you Google "Ryan's guide to halogen bulbs" you'll find the best halogen bulb for application. If you want the best, then a retrofit with the MD2S with the shield drop mod, denso ballasts and osram CBB or CBI bulbs would be the best. Then there are in the middle retrofits you can do.