While out with a drive with some other Xfire owners this weekend, I noticed something I had never seen before - small, but noticeable, vortices coming from the rear above the wheel arches on the car in front. It had been raining a lot, and there was a lot of moisture in the air, on the roads and it was curling around a little bit each side of the car ahead of me. Just the right kind of conditions for these air currents to become visible.

No picture, I’m afraid, as they were fairly fleeting (and I was driving at the time), but an interesting thing to see in the real world, and not just on TV programmes about aerodynamics.