I have a 2003 zx3, I have HID's setup in my car, this problem still accured with my halogens but wasnt as noticeable because they didnt shine the road as bright. When I go over small bumps in the road or big ones my bulbs must bounce up in down because on the road they move real fast.. its extremely annoying. Its kinda like a flickering. The bulbs are NOT dimming, and I noticed that where the bulb sits in the housing is like spring loaded, I can move it up and down.... whys that and is that my problem? is there a way I can tighten it down?