This raises the question of whether these checks apply to vehicles fitted with after-market HID lighting kits. These kits convert conventional halogen headlamps to HID Xenon and they are widely sold and fitted to vehicles used on the road. The Department for Transport considers that after-market systems should be required to meet the same safety standards as that applied in respect of these lamps at vehicle Type Approval. Therefore, in order to pass the MOT test, vehicles fitted with after-market HID systems would also need to be fitted with headlamp cleaning and self-levelling systems. Some high specification estate cars are fitted with a self-levelling suspension system and this would be considered as adequate for the purpose.