The only way HID's are Legal is if they are in fog lamps or spot lights, or if you want them in your head lights they either have to be factory fitted, or if they are after market you must have projector lenses as this gives a sharp direction of light and doesnt scatter it like standard lenses, you must also have washers that spray your head lights when you spray your wind screen, and you must have self leveling lights, or it will not pass the MOT, but apparently they are fine in spots and fogs as they are not tested in an MOT