I´m from Denmark, so dont know the rules in the UK. But when you put Xenon lights on your car, it blinds the oncoming cars, because your car doesnt have Lenses in the light to disstort the light, so it doesnt blind people. You also need to have headlight washers and self-adjusting headlights. Here in denmark you get a fine of £120 for each headlight, if you get pulled over by the police.