James on: clip-together cars

The problem with Meccano is that it looks so old-fashioned. Because it is. It's a 110-year-old toy, inspired by the engineering structures of the Victorian era and before, when the means by which a thing went together was something to be celebrated.

So, look at the roof of St Pancras Station, the famous Palm House in Kew Gardens, any old bridge, the ancient Aga in Richard Hammond's kitchen or the exposed motion work of a steam locomotive.

Bolts, rivets and linkages are openly on display, and if the decorative skills of the artisan were to be encouraged, then they were applied to the structural members themselves, not added later as an adornment.

That's why Meccano looks a bit stuffy. You can't make something from Meccano without it being plastered in screw-heads, nuts, springs, exposed gearwheels and everything else in that big red box.

Before the war, Britain looked like Meccano. But by the Fifties, it was starting to look more like Lego: bold, relatively featureless shapes with smooth surfaces, apparently made not from thousands of small pieces but from just a handful of big ones.

Modules, maybe, but not components as such. That's why anything you make in Lego looks modern, even if you only use the grey bricks.

Now look at the things around you - your mobile phone, your kettle, the interior of your car. How were they put together? It's difficult to tell, because you're not meant to know.

Why the hell am I talking about toys? Because, eight years after I made my one-off Christmas documentary about my most favourite toys of childhood, I'm still making TV about toys. The subject truly fascinates me.

Contrary to what some people think, I'm not against modern toys at all. I actually think computer games are tremendous. I especially like the FIFA football app, and I've now got an Xbox. Admittedly, it's still in its box, but I've been busy with my nephew building a Lego Technic helicopter.

But the enduring constructional toys are deeply instructive. All of Newtonian physics can be taught with Scalextric. A train set can do a useful job around the home. Airfix is a great way of learning history. And so on.

Last Christmas, you will have seen - I presume, but if not, why not? - that I built a full-size Meccano motorcycle and sidecar, by which I mean I thought of the idea in the pub and then instructed my mate Simmy to get on with it. It worked tolerably well, and it had me thinking.

I once built a full-size and inhabitable Lego house (same qualifier as above), and, although there were issues with the plumbing and the rigidity of the furniture, it made a lot of sense to me. If you live in a Lego house and want to modify it, you just pull it apart and rebuild it in a different way. There's absolutely no waste.

The real world of building is different. We recently had our bathroom modified and it produced a skip-load of useless rubble. What became of that? It may at best have become hardcore for a new bit of road, but it probably just went into landfill somewhere.

No one could argue against the case for a reconfigurable house. Why not an infinitely reconfigurable small car? We're told that this is already with us. BMW allows you to adjust the power output from the driving seat, and all sorts of cars allow you to interfere with suspension settings.

But this is merely the distracting tinsel of electronics. I want to be able to pull the whole thing apart and put it back together in a new way.

I have in mind a kit of parts combining the best attributes of Lego and Meccano - Meccano for the mechanisms, clip-together Lego for the bodywork and interior. Sort of like one of those do-it-yourself Caterhams, but you decide how it comes out.

If the future of the car is electric, this becomes a lot simpler. Your kit contains an electric motor - it'll be quite compact - and a battery and control system. A bit like Lego and Meccano as they already are, in fact... just a bit bigger.

We all know roughly how a car is laid out underneath. Have a go at it yourself. If it doesn't work, try again. No welding, no painting, just a few spanners and bits that clip together. Children have been designing and building table-top cars for generations. If we make the parts bigger, we could actually be using them.

It's easy to knock this idea. What if, for example, you got the fundamental suspension and steering geometry wrong? Isn't that a bit dangerous? Possibly.

But, as I said, constructional toys are educational. If your apparently workable small car goes into a sudden and uncontrollable weave at 55mph, then flips over and disintegrates... well, you'll have learned something.