Ok..here's the pic: BUT think I've worked it out now. When I originally asked him about it, he said it was his private plate: I now think he took it off his other car & added it to the S1 for the show so peole knew who's car it was..and it's NOT its normal plate.
So: need to get the real plate number now
Then I'll update the database..but leave it at L5TUY for now so it doesn't get lost.
Thanx to alan @ rscarshows for the pic