I renamed your thread to "License Plates" (removing US) to include few links for other countries.

So there is the British license plates site, at http://www.vehiclelicence.gov.uk/EvlPortalApp/index.jsp -> "vehicle enquiry"

For French plates there is http://sfpi.asurtech.com/histo.php3
But as the car plate changes when it is sold in another department, it only gives the date of the last registration. It can be useful anyway.