At the risk of sounding like a complete idiot, I'm going to ask this question simply because I don't know the answer, and I'm sure someone here does.
Concerning HID systems.........
I see quite a few cars that when they are approaching from the opposite direction, the lights have a slight blue tint to them. I know this is normal. BUT......as the cars pass and they are at roughly a 30 degree angle to me, the blue tint changes to what a standard halogen would give off, kind of like a pale yellow. I think, correct me if I am wrong, but I think that these could be fake hid lights...(colored bulbs). I've seen a lot of ricers that do this, and a few older Beemers. I haven't noticed any new Mercedes do that. Am I correct in my assumptions that these may be wannabees trying to get the HID look without spending the bucks? Or am I crazy?

 

I think that almost all the HID's I see at some angle do what you are refering to. I know I have seen some newer high end cars that do so I don't think that its a replacement bulb. I have wondered myself why they do this and I never came up with an answer. I know I have aftermarket bulbs that are bluish tinted and to me they look better than the standard yellowish look, but they dont have the HID look to me. This is probably of no help but thought I would chime in...