Even if you haven't heard of these new headlights, you've probably noticed the occasional piercing "bluish" flash on the road at night. HID headlights are already being fitted to up-market European, Japanese and American cars.

As you might have guessed, the technology used in these headlights is radically different from conventional tungsten-halogen headlamps.

Not only are HID headlights much brighter, they are much more efficient and draw less current from the battery.