I don't know who thought of it but it's certainly a good idea.
Someone has been putting a sticker of a fish on the back of the cars of people who are sh*t at driving.
Have a look next time someone is doing 25 in a 60 or not indicating on a round-a-bout, chances are you'll see one.
Obviously not all bad drivers have the "I can't drive" fish but it would appear that all people sporting the fish sticker can't drive!