I just installed some 6000K D2S bulbs and drove around last night. I found out that there is less light projected onto the pavement. So, is this a problem with the bulbs or do I have to adjust the headlights (up/down?).

 

Check out some of the other threads on changing the HID lights. Any thing other than the OEM HID rating will put out a different wave length of light which will cause less light reflected back to you to be seen by the human eye. It will make the headlights seem dimmer behind the wheel even if the output is same or more than OEM.

Any thing close to actual sunlight wavelength will give you the best and safest beam pattern at night. Any thing else is for the "cool" factor.

 

But yes, you can easily knock the focus out of whack while working on them (or changing bulbs). I had to adjust mine drastically after putting in the new housings.

Search here, there is a thread w/ a scan from the service manual as to exactly where the up/down and left/right adjustments are, but its something you can easily do yourself. Remember to go park 15 feet from a nice long flat wall somewhere so you can get it juuuust right. I used a Costco after hours.