I had been blithely assuming that Xenon Plus bulbs were a replacement that used similar technology to the high-intensity Xenon lights you see on new Mercs, Lexuses (Lexii?) and police Vectras.

Not so, it seems. The only thing in common is the presence of Xenon gas inside the bulb envelope. "Real" Xenon headlights have no filament, but use gas discharge (a la strip lights), and hence need a high-voltage supply, a starter and a "ballast" or choke.

They also have to warm up, so you can't "flash" them. For this reason, all the factory-fit systems use incandescent bulbs for the high beam.

Xenon plus bulbs simply use xenon gas to replace the more usual halogen, which gives a slightly different colour temperature but nothing like the very blue-white light you get from true high intensity discharge (HID) lights.

If you want to know the full story, check out this excellent FAQ:

http://www.legend.org/performance/mods/xenonfaq.html

It looks like a proper HID conversion would cost the best part of a grand, but would take some beating for coolness. Who's going to be the first then (Anders? ;o)

-= mike =-

Also, in numerous conversations with a Techie from Osram, Xenon bulbs are NOT suitable for MY99 cars-They do fit, but are designed, at the moment, for std headlights not parabolics (as fitted to MY99s)
Could be why those that have fitted them to 99s say they are not that good?

Emm. Interesting, anyone else got any comments on this? Fitted them in my new car from the outset. They do give a "whiter" light but that's about all. Mind you, I don't think that lights in the MY99 are quite as crap as some people have commented. I do quite a few miles and consider them a fair bit better than my MY97 (not that difficult I suppose).