Sad to say but most people who have the Ultinons that got it from Ebay or E92 lighting, are knock-offs, even though they have the Philips markings etc. Ive searched long and hard and just couldn't find authentic Philips 6k bulbs. If you do a quick google search you will find that many people found them to be fake. Simple because Philips does not make Ultinon D1S. And usually the knock-offs are labeled XenStar or Xenstart. And you cannot buy from Philips direct from USA because law prohibits Philips to resell those lights here. Only way was to get it overseas and the last time I was in Europe I went and got a set at a Philips authorized retailer. My Philips 6k are NOT Ultinons. They are in fact just called "Philips Ultra Blue". Philps Ultinon was only made in D2S (E46/E39) and D2Rs (previous gen Audi).
Here is a picture of what mine looks like:
The bulbs are amazing and way better than the previous Ultinon I had on my E46 M3. The new bulb are actually extremely cool because the light they project are actually dual-color. They are 4300k in the middle of the beam, and around 5800k around the far left and far right corners. Philips says its to reflect off road signs better while providing better visiblity further down the road with with the warmer temp in the center. Ill take a picture maybe later tonight to show it but its very cool. It was not cheap at around $280 a set, but its well worth it.