It's an early bay with a 1978 registration plate.
Probably just a TV number plate, lots of vehicles used in TV and films don't have their own registration plates fitted.
@Coda its the bus in the attachments dude.. @sparkywig you got it. I wonder why though. Its seems some did and some didn't back in the day. Like the Auf Weidersehen Pet brown bay. Im sure that was the registered plate. @YellowBay69 i never play that. Honest. .
Sliding door on wrong side for uk, yellow headlights and body coloured nose badge suggest it's an import. As Sparky says they probably stuck a "TV' plateon it to save any legal comebacks etc. Legend has it that the "Return of the Saint' series (Ian Ogilvey as Simon Templer" was filmed abroad as they couldn't get permission to use the ST1 plate in the UK. Lots of Ford's used in The Sweeney had Essex number plates as Ford's publicity dept were based there. I'm off to iron my anorak and do some train spotting