Hey Aalap,
Let me clear a few things out.
1. The bright white headlamps with a tinge of blue you see on cars like the Mondeo, S350L, Skoda L&K, are *REAL* Xenon lamps.
The similar kinda light comming from a modded lancer/city is basically just for the purpose of trying to immitate a xenon.
*REAL* xenons (the ones with the real advantage) are filled with xenon gas, and do not have a filament. The light is caused by an arc of electricity jumping across two electrodes. It takes an incredibly high voltage of ~50,000 volts to start this arc.
2. Any bloke trying to sell you a H4 bulb, running on 12Volts, with a filament and claims its xenon doesnt know what the hell he is talking about....(and believe me none of them do).... Manufacturers have caught onto the whole 2F2F scene and have started labeling their bulbs as "xenon"...they probably put in a bit of xenon to support the claim, but in reality these are not xenons and have none of the advantages of xenons. A real xenon system will probably cost 50k or more, including both lamp assemblies as well as some kinda step up for the voltage, and maybe a self leveling system.
3. Even IF you had real xenons, its still debateable as to whether or not they do have an advantage over halogens. (See the link provided at the end of this post)
4. To get the best bulbs, what you want to do is buy a higher wattage bulb, 100w/90w (highbeam/lowbeam vs the stock 60/55w). However, to use these safely and to their maximum efficiency its important that you have a relay as well as wiring harness put on. I have done this in my car and its totally worth it.
Also, the quality of bulb is important....ie buy from a company like Philips or MICO etc...
5. Headlight alignment is ABSOLUTELY CRUCIAL to getting the best performance out of you headlamps. On low beam, when you are facing a wall about 20-40feet away there should be a clear line at the top of the projected light, and that should be lower than your headlights (ie the lights should be pointed slightly downwards...otherwise they will end up in the eyes of an oncomming motorist). You can manually adjust your headlamps by yourself with just a screwdriver or coin(gotta love mercs... atleast the old ones).
Also, this is very important when you have overwatt bulbs since the lights are much brighter and blind oncomming drivers very easily.
6. What i dont like about the "blue" bulbs, is quite simply this> they provide no added advantage, and in some cases even lower the visibility. But what i hate the most is that some makes of those bulbs absolutely blind oncomming drivers with blue-ish white light irrespective of highbeam/lowbeam!
Well thats about all i have to say.
If you are even remotely interested in this issue you shoud definitely check out the following site and read all the articles listed on the page it opens to >
Daniel Stern Lighting.
cheers
R