It's like when I lived in California. You were supposed to have a front and rear license plate on your car. I rode in my '73 challenger without one for 10 years. I got one ticket and that was only because the cops were looking for something to get me on and circled my car three times and that was all they came up with at the time. Yes it is illegal to run without one but they did not go out of their way to enforce it. If they enforced every thing that was on the books then they wouldn't probably get more than 100 feet without pulling someone over. The letter of the law and what is enforced are usually two different things from a fix it ticket standpoint. Probably not enough to worry about unless they are gunning for you already or need probable cause for a stop.