Audi Repair: Rplacing Headlamps/Bulbs on 2003 A4, xenon headlight, xenon bulb

Question
I'm thinking of changing the standard headlamp bulbs with some HD ones, is this possible or are the units sealed and have to rpelaces as a unit?  

Answer
hello
If you thinking about switching to xenon light, you have to replace whole unit to have xenon beam. Some people mount xenon bulb inside regular headlight and module(igniter) outside, but the light is not as good as original Xenon headlight. It's up to you what you want to do. Both lights have the same connectors and mounts.
good luck .  Greg