> Because they are harmless fun? Many hours of road trips were spent trying to spot a license plate from every state. In Europe that's possible too. Aside from

> Because they are harmless fun? Many hours of road trips were spent trying to spot a license plate from every state. In Europe that's possible too. Aside from collecting all the countries, you can collect the cities. For instance, plates in Berlin are of the form "B-AB 124" but plates in Hamburg are of the form "HH-AB 124". Presumably you can't really collect them all - there's too many cities - but you can try to work out what they all are.