D1S Xenon Headlight, HID kit alternative...
 

When I bought the car, only the driver side had the ballast and bulb, the right side is missing the ballast and has a regular bulb. Looking around I see the ballast for over $200.00 + bulb.
My question is, if I decide to go with an HID kit, which bulb size should I pick? Also I see these bulbs (picture) will they work?

http://www.xenongate.com/images/D1S.jpg

What year, model and engine is your car?

2002 A4 1.8 Quattro

when the ballast on my A4 failed, I bought a ballast of a Chrysler 300.. Its the same part with a tiny modification to the harness. Here is the thread for reference:

new twist on ballast replacement - Page 2

The ballast cost me ~ 160.00... just thought I'd put this out there as an option