Battered old white van that has a police siren and blue flashing lights in it radiator grill?

I've seen this twice this week flying around with its siren on and its police lights flashing jumping red lights and flying down bus lanes etc and to be honest the driver looks like an aged Mediterranean man and he always has a passenger who is an old woman in the passenger seat.  Has anyone else seen this van? It looks so unlike a real police van and looks like someone has kitted their van out with the lights and a siren to get around the borough without having to worry about the traffic congestion.