Re: And this ladies and gentlemen...
I'm going to have to disagree with you there.
My current car has the letter "O" in it's registration, and a previous car had 2 letter "O"s in the registration.
In the UK and Aus case though, the number plates are deterministic. You know which are letters, and which are numbers. Perhaps the ticket machines didn't have a QWERTY keyboard, and were confusing to use.