Creating a 3d effect using vector

Hello, I’m trying to design a corporate website using many shades of grey. What Im trying to do is make a white line go from left to right, and look 3d. what i mean is:

go to, and watch the loading bar, it looks sort of like it’s moving towards you.

I included what I’ve got so far (using Fireworks), but it doesnt look so good. I want it to move quickly, and at the same time 3d. I’m trying to stay away from raster stuff, because i need this to load quickly.