vanity plate 

A special type of vehicle registration plate on an automobile or other vehicle. The owner of the vehicle pays extra money to have his or her own choice of numbers or letters, usually forming a recognizable phrase, slogan, or abbreviation on their plate.

I once thought of getting a vanity plate that say FA-Q or FA-QUE. But then I decided it would be better not to have my windows smashed.

vanity plate by Progressor February 8, 2014