As the crowd waited for the unveiling on the new Audi A7 last night in Munich, our attention was momentarily captured by its red-trousered chief designer, Stefan Sielaff, as he positioned lengths of black tape on a large, hanging white board.

The important thing, he explained, was that there were only three lengths of tape: you have to be able to capture the essence of a car in just three lines.

And that’s exactly what he did. It’s not so much that you couldn’t see these lines already - you could because they were pencilled on the board - but it emphasised them in a slightly neater way than, say, going over them with a large black marker, Rolf Harris-style.

What was particularly striking, as you can see from the picture here, where he's put just two lines on, is how the slight divergence between in the two lines across the door - the swage line and the waist line - adds a sense of dynamism to the shape. It somehow superimposes a wedge-shaped purposeful poise on the car.

I’ve only seen the A7 indoors, where the major lines are all but hidden by the glare of the camera flashes and spotlights, but I’ll be interested to see whether you really get the effect in the open air, where the car will spend its time.

See what you think, by watching our 360-degree video of the Audi A7, filmed at the launch in Munich.