Most versions I've seen look like this one
(it's on Archive.org so I reckon it's alright. If not feel free to delete it)
http://archive.org/details/1979StarWarsDrunkDrivingPSA
They probably originate from that.
While this one on youtube looks fairly decent.
http://www.youtube.com/watch?v=a0JQid50UNE
For one thing, the colors are correct and the speed is finally right.
Jedit: although upon further inspection, the blown out copy looks like it has more stars.