I ordered a fiber optic illuminator (ie: http://www.starceiling123.com/index.php ... k.tpl.html and some fiber optic strands. When they finally arrived is when I realized this wasn't going to be a walk in the park (drop the headliner, poke hundreds of holes in said headliner, etc..) , so they just sat in my room for a while. I really didn't want to drop the headliner,thinking it would take forever, but I finally forced myself to get started and finished in a few hours. (Side note, I'm like this with everything: I make mountains--like Olympus Mons sized mountains-- out of molehills and have a hard time starting things. But once I start I'm usually fine.) After dropping the headliner I printed some star constellations and used them, with some hand drawn ones, to layout my star field. At first I tried to keep everything sort of correct as to how one would see them in the sky, but that didn't last too long.
Here's a pic of what the fiber optic strands look like while I was putting them in(poked a hole with a thumbtack through the back, ran the strands through them, then when finished, used a nail clipper to clip off the excess on the front side):

I should add that I used a glue gun to hold all the strands in place.

This took me a couple weeks of a few hours of work a night when ever I could spare some time. When all was said and done with the fiber optic strands it was time to put the headliner back in the car! This was a lot harder since there was a lot more weight on it now, and it was hard to shimmy it back in without it bending on me and harming the rigidness of the it. I ran all the fiber optic strands together down the back passenger side of the car and they came out where the little storage area is back there. I ran an extension cord under all the plastic and carpet from the 115v outlet to the storage area (that's where the LED illuminator is hidden for the strands).
The end result is a cool, sparkling, multi-color, star field in my car! I can change the colors, twinkling speed, etc... They aren't bright enough to distract me while driving, and can barely be noticed if looking from the outside into the car.
Here's a video of it (click the picture and it will jump to the video):
