My driver side headlight started randomly going off recently, then completely failed. I assumed it was the bulb and was about to purchase some replacement HID bulbs. While searching, I found a video on YouTube of a guy with the same problem. Turns out the light wasn't bad, but the 20amp micro stubby fuses (#15 for the drivers side and #16 for passenger side) were melted. HE replaced his fuses and the lights worked, but he never explained what caused them to fail. So, I pulled fuse #15 and sure enough it was burned. I replaced it with a new replacement and my headlight works again. I don't know if anyone else has experienced this, but I wanted to share it so others can be aware of it. It's much cheaper to replace a $1.50 fuse than to replace the $68 HID bulb.