What to do if you are pulled over by an unmarked police car.

Brian,
I enjoyed the video blog you recently posted about how to get out of a ticket. I frequently drive alone late at night and was curious if there were any pointers you could give me regarding unmarked police cars. Are there distinguishing lights or anything like that I can look for and be comforted that it is a legitimate police officer who is pulling me over? What actions can I take to insure my safety when getting pulled over at night in deserted areas?
Thank you!
Elizabeth