Audi TT Intermittent headlight

Did exactly as you said, replaced both bulbs with the d2s as you said and got them on ebay, driver side was clearly more difficult to put in, passenger side very easy, worked perfect for 1 day and the intermittent problem returned. What to do.

I'm having the same problem with my 2004 TT. I've narrowed the problem down to being the bulb. I swapped bulbs with the driver side and the problem followed the bulb. Your solution is to replace the bulb. You need a D2S 4300 K bulb. It's best to replace in pairs. Try here: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=290310078483

You can change the bulb easily yourself in about five minutes, especially on the passenger side. You may want to disconnect the battery, though I don't know if that is necessary. You may also want to handle the bulbs wearing latex or nitrile gloves so as to not get your skin oil on the glass.

1. Remove the decorative cover that conceals the Coolant reservior. There is a single philips screw near the firewall that holds the cover down.

2. Find the back of the headlight and pull the metal wire clip that holds the back of the headlight cover toward the engine. Remove the cover.

3. Look inside and find the back of the HID bulb--it will be toward the outside fender. Twist the connector until it separates.

4. There is a retainer ring that holds the bulb in. Again, twist that until it comes loose. The bulb should come right out.

5, Put the new bulb in, noticing the notch is on top. Also, attach the retainer ring. It is marked "Top" to help orient it. Reattach the connector with a twist.

6. Make sure everything is firmly in place. Reconnect your battery and test the lights. Finish putting anything else back on.