I disagree that it's untrue. You knew that it said "authorized vehicles only," and you knew that you didn't have authorization.
No reason to think it isn't.
I doubt that's true, but I have no knowledge of how this company, which helps "cities, counties, [etc.] collect payment on outstanding debt" runs its website since you can't get past the home page without information about a particular ticket.
When you called the (800) customer service number, what happened?

