Front passanger head light?

I would check that both black retaining clips are pushed down all the way, and are hooked onto the headlight. Also, check to make sure your bulbs are in all the way with the locking ring on tight and make sure you still have that o-ring on the bulb.

BTW: I was reading your mods, similar to what I'm going for with my car, just curious, have you run it in the 1/4 mile yet? Dyno'd? What are your numbers?
 
I would check that both black retaining clips are pushed down all the way, and are hooked onto the headlight. Also, check to make sure your bulbs are in all the way with the locking ring on tight and make sure you still have that o-ring on the bulb.

BTW: I was reading your mods, similar to what I'm going for with my car, just curious, have you run it in the 1/4 mile yet? Dyno'd? What are your numbers?

My numbers are in my sig. Right now I'm 280rwhp and 300tq. That's with stock headers, a catted H pipe and dynoed on a mustang dyno. I have long tubes on order, 4.10 gears going in and I'm going with a VRS catted X pipe. I should be around 300-310rwhp after that. She already pulls like crazy and I pulled a head on a GTO today.
 
I got some aftermarket headlights and the clips that hold them in were a little bit looser then the stock ones so I put a strip of electrical tape on both sides of the clips and now they dont shake anymore. Also a cracked or loose header pannel ( the plastic peice that the headlights clip into) will do this.