*(I just discovered this sub and immediately subscribed.  This place looks right up my alley!)*

I've got an application that analyzes a user-submitted license plate and attempts to validate whether it's in a proper format.  I do this with a dataset containing possible regex combinations.  

For example, the state of Alabama may have plates in a format of:

    [0-9][A-Z]{2}[0-9]{4}
    [0-9]{2}[A-Z][0-9]{4}
    [0-9]{4}[A-Z]{2}[0-9]

(or any of a number of different combinations).  

Arizona might have plates in the format of 

    [0-9][A-Z]{3}
    [0-9]{2}[A-Z]
    [0-9]{2}[A-Z]{2}
    [0-9]{4}

etc.

I've managed to kludge together a list of a couple thousand permutations for the US and Canada but it's still very incomplete.  I still find perfectly valid plates that aren't being vetted as correct.  And I don't have any data at all for Mexico.

Does anybody know of a good source of data for this?