There seems to be competition these days as to who can get the brightest lights with some drivers replacing their car's normal bulbs with ultra bright HID bulb kits. Though I doubt they will have informed their insurer, if they bother getting insurance that is, that they have done a modification.
Quoted from the website below. "You can fit an aftermarket HID kit to a UK vehicle, and as long as the beam pattern is correct, the light is predominantly white or yellow-white, there is no glare for other road users."
The majority mustn't be road legal then as some are dazzlingly white and blind oncoming drivers.
Are HID bulb kits legal in UK