Hi,
Light Emitting Diodes (LEDs) certainly have become useful in many applications to day. However, it seems as though they are not yet very practical for applications such as headlamps, because that would require the use of White LEDs. White LEDs are still the most expensive to produce, so the price would be high. That's probably why you don't see many people making LED headlamp modules.
-Nick

__________________
1988 Jeep Cherokee w/ 410,000+ miles. Now a
100% Electric Vehicle!
NO Gas, NO Emissions, NO Problem! --
http://www.DriveEV.com/