You're right about cops being astute. That's why I tend to level with them and get warning more than tickets (not that I have tons).

The RFID idea is cool, w/ one caveat of course, the tag is for Johnny citizen to say "I saw the tag and it was ......" , low tech sometimes is better.

Of course how many people see the front and can't see the back? I agree why a front to begin with, I'm sure there's a night of google to find that answer in history!