Just noticed that one headlight is slightly yellow only when the headlights are on. I have looked at the lens or the lens covers in the daylight and both look clear no yellow haze. I was thinking if the actual bulb was going bad or loosing gas? Not too sure if it possible. If so, what make and what type of xenon bulbs do a 2005 Carrera use?

 

Most likely Philips but you have to remove it to know for sure.
Here's what Suncoast carries.

http://www.suncoastparts.com/product...de=997S_Lights

 

Yeah HID bulbs can go funny colors when they go bad. Just be glad yours isn't hot pink.

 

Happy to hear it might be the bulb, a new headlight is a whole lot more $$$ to replace.