Garef said:
I read recently that it's nothing to do with the actual bulbs being illegal, it's the lens, to make them legal you must get a lens that is specifically designed for the bulbs, something weird like that.
That's right mate. They won't measure light output at MOT time, just where the beam pattern is aiming. The same would be true if you got pulled over by plod, and one of the inspection unit officers checked the car over....
CanadianR said:
forgive my stupidity, but do GTIR headlights have reflector housings or something? HID's are something I have wanted to look into for the car for a long time, but supposedly putting HID's into headlights with reflector housings is a bad idea (too bright or distracting for oncoming traffic?)??
Exactly mate. Any light housing/optics designed for halogen bulbs, simply won't function correctly with HID lights due to the 3 fold increase in light output. This will result in spikes in the light pattern on the road and/or extreme glare for oncoming traffic.
You'll notice that cars fitted with HID lights, usually utilise projector type housings/optics (like a minature fish bowl). These have a piece of metal inside, that is shaped in a distinct way, to cut off the light output at a pre-defined height, as well as the internal shaping of the optics.
When I fitted my kit, I needed to lower the beam on the O/S/F just about a qtr of a turn and it's been fine, not flashes from anyone. Because of the sheer amount of light on the road, you'll not notice the difference in the slightly withdrawn beam pattern.
I left the N/S/F as it was and it lights up road signs from miles away but, again, if I sit behind a car, at a decent distance, the beam pattern height is still way below where it would cause glare in the rear view mirror. In fact, it's usually half way between the bumper and bottom edge of the rear window.
Paul