Wheel covers.

just put a weight on the bottom of a "spinner" ??

BUT!! what's the point in adding the weight and drag? oh.. and looking like a complete Chav?

johannes gurgled happily, sounding much like they were saying:

As Loopy suggests, merely weight one side of a set of spinners.

Have you never noticed the hub odometers on HGV trailers and on many buses? They do exactly what you're looking for - and work in that way.

But aren't these just a uniform disc, so you don't notice if they are staic?

I think there was once a picture in a car-mag of a prototype wheel or tyre design where the entire wheel was static, but with an outer ring (or tyre) circulating around the main wheel. Wonder how the power was transmitted to the road?

there was a bmw mini converted to use a special electric motor at each wheel rather as you describe, it was built by aerospace engineers and I read about it around five years ago. I imagine the motor units are something used on planes ?

johannes gurgled happily, sounding much like they were saying:

Friction or gearing to the rim.

I think they go in the same box as furry dice.

Apart from from really sad, they are possibly dangerous, as you look at wheel rotation to work out whether a car is moving or not - car in junction to your right, wheels spinning - its pulling out? ditto, wheels static, its stationary - not its not!

Crap.

(if it doubt, refer back to some driving manual when I learned to drive pointing out that wheel rotation was easier to spot than car movement.

God point that. It reminds me of some drivers who push forward out of a junction or roundabout in the expectation that an oncoming diver will continue at same or higher speed. If the oncoming driver slows down for some reason, then he is likely to crash with the forward driver. I.e. the forward driver forces you to 'hurry'. I don't know if there is a name for this behavior, but finds it annoying.

this was the mini I was thinking of:640bhp 4wd electric mini built in the UK by PML

I think it's illegal to have the wheels sticking outside the wheel arches. But I remember that wheel extenders was once a popular extension type.

Normal people who don't know how to drive, possibly.

Movement of the front wheel is visible long before movement of the vehicle.

Rolls Royce.

that is a common misconception that even the police believe, according to construction and use regs you must have half of the tread covered and not make excessive spray when it is wet IIRC

I thought that was just the emblem in the middle ?

he aint gonna buy one anyway :)

I'm sure it is possible to drive safely without making use of that tip. Making fun of it without thinking about it or trying is what makes me think you are no driver. Congratulations on your luck - I hope it never runs out.