Iirc the prototype (number 0001) was crashed & written off by a journalist. Apparenlty it wasn't a full Williams, but a valver with a few bits on it.
No one really knew about the car in the vid (actual willy 0001) till a dude from here dug into it, he has number 0002 When he went to the renault museum etc the willy wasn't on show but hidden out of sight.
He put up some pics of it when he went there. Said person was banned (from here) long ago.