In the Autocar car park, there's a tree that partially blocks a marked-out parking space. The space has, unsurprisingly, remained unused for months. Until, that is, Autocar began running a Smart long-termer. The three-meter long Smart is the only car that can squeeze into the space.

DSCF2741 The upshot is that the smallest car on the fleet is also the only one with a guaranteed parking slot.

Which is why I have to remain on the fence about Toyota's remarkable IQ. The fresh thinking and bespoke engineering that's gone into making a 3m-long car that can accommodate at least three adults (and that drives like a much bigger car) is hugely impressive.

But does it need to be that short? Perhaps there are thousands of drivers in the UK (the hints are that Toyota would like to sell 10,000 IQs per year) who look at the IQ and say, "Yup, just the job."

Perhaps you struggle to park on your daily commute and know just the spot you could squeeze an IQ into. Or perhaps it's the only second car that will fit onto the driveway next to the full-size family car. Perhaps.

_t3k0904But the IQ does not offer radically better fuel economy than a supermini, nor is it cheaper. It has less luggage space and less interior space -as brilliantly packaged as it is. Size matters, but I'm not sure that having such a tiny car is as big an advantage as might be claimed.