Cops have better things to do in San Diego and SoCal than to cite folks for having no front plate......
Having said that, I will admit that if you are pulled over and give the officer a hard time, I'm certain that he or she would be overjoyed to add that to your list of violations.
Attitude is everything.....
However if you live in an area specifically designated to rookie training, or if you happen to reside with the Keystone cops.....(read Goober, Gomer and Barney Fife)... then almost anything can happen.....
Bottom line is that car stops are dangerous... I wouldn't pull someone over in an urban environment simply because they had no front plate.....
SD