That be an invitation for The Law to pull you over. Happened to me a few years back when the front plate on my '79 Suby got ripped off when I plowed into an ice-packed snow pile one snowy day. I tossed the plate in the back until I would get around to putting it back on. Three days later, I got pulled over by Smokey when I was leaving work. Got a warning only. Still, never give The Law a reason. Always be compliant.I am in a state that requires it - but never use one.