LOOK, I'm going to show you how to become invisible.

Ready? Good. Here's all you have to do: get a job as an actor in an American drama series.

Your role should preferably be that of cop or investigator. You'll be assigned to watch someone entering a building or making a drug deal.

That person will be right hard, and suspicious as hell, and will be looking around to make sure they haven't been followed. They'll probably be scowling. Bad guys never lighten up.

They may stop in the street before they enter the building. But they won't see you, probably with an equally cop-looking buddy, in a car parked just across the way, or even right in front of the building entrance.

It's uncanny. You get in one of these cars and no one can see you. Now, I have agonised — or caused agony — before about the over-used American TV drama device of having people fall unconscious from the slightest poke in the snoot.

In Star Trek, they did it willy-nilly, and not always because of Mr Spock's Vulcan nerve pinch. In most cases, it was just a punch, sometimes to maybe three or four people. One after the other, down they went like skittles.

I don't think it was just American drama either. I'm sure the Saint could knock people unconscious just by raising one eyebrow.

It's a handy dramatic device, minimising the hassle of common or garden baddies getting in the way of the plot by fighting back and refusing to black out.

The invisible car scenario likewise allows easy spying on hoodlums. It was used a lot on The Wire, a supposedly sophisticated show. We used to watch it and say: "They're in the invisible car again."

It was positively ridiculous. Surely, if you were up to something, and had reason to believe you might be followed, you'd notice two uncomfortable-looking guys sitting in a car parked right outside your house or office or torture chamber.

I notice everything that goes on in our street, and I haven't even done anything. It's not just me. The fact that nothing ever happens in our street means that if two tough-looking guys turned up and sat in a car, a sizeable crowd would gather within seconds.

I suppose that's why they've never made a crime drama like The Wire set in our street.