I have an 02 A4 3.0 and my passenger side HID just went out. The display tells me "RIGHT DIPPED HEADLIGHT". I tried turning it on the off again numerous times to see if it even tries to turn on. Nothing. The bulb does not even flicker. This leads me to believe that it is the bulb that is the problem. Had the problem been with the ballast I think the bulb would at least flicker. This has been my experience with HIDs.

Can anyone confirm or correct me?
If I am right, can anyone suggest where to get a new bulb?
Your input in much appreciated.

 

I'd suggest swapping the bulbs left to right to confirm you've got a burnt out bulb before going out to find a replacement.