Hi Little Jane - I can't help with the name of the site but something like this does exist. Not necessarily if it's been damaged or in any accident at all, but to check that the vehicle is genuine and not a cut-and-shut, for example.
When we were buying our Landy, the guy who was helping us asked for the registration number so he could check for us. As it is ex-military there were some issues obtaining the records with the old registration alone, but once we provided the chassis details it could be done.