Maybe try car plate sql injection. :D http://1.bp.blogspot.com/-URBVGKEBRss/U0GgQetIwEI/AAAAAAAAC2...

Wow. Problem one: applicant writes "no plate" instead of leaving it blank or writing in a crossed line. Problem two: so do the law enforcement officials! The former is a silly mistake; the latter should be a learning opportunity.