This vision of a 2021 bread van is, in fact, a near-production VW city car capable of an astonishing mpg rating. In a tantalising green reversal, the VW Up! Lite's eco credentials read like the two important numbers should actually be the other way around: 65g/km of CO₂ and 116mpg combined.

The best thing about the Up! Lite is that, contrary to what those figures would have you believe, it's not too far away from production because VW has ensured that, mostly, parts with a modicum of affordability are used. Of course, some of the bits have no place on a supermini, like the reversing cameras and carbon fibre, but VW is adamant that much of the Up! Lite is destined for showrooms in a generation's time. That'll be when the Up! family of green cars starts filtering through, beginning in 2011 and with a full electric car due in 2013.

Power for the Lite comes from an 800cc two-cylinder diesel engine developing 50bhp and linked to a 14bhp electric motor that both boosts power when needed and can drive the car alone at low speeds. A seven-speed dual-clutch transmission handles the cogs, with performance surprisingly brisk: 0-62mph in 12.5 seconds and a 100mph top speed.

The diesel hybrid powertrain would be impressively economical enough in most city cars, but with the work VW has done to make the Up! Lite so light and slippery, it's no surprise the concept is a green pioneer. The engine itself has been pared back to weigh just 55kg - which in old money is just under nine stone - and the total kerb weight of the car a mere 695kg. The grille is active, closing off for better airflow when it's not needed for sucking cold air in. The car's drag coefficient is 0.237, and if that means nothing to you (which is perfectly normal), know that the original Lamborghini Countach, which still embodies car wedginess, had a comparatively boggy 0.42 rating.

The interior is a picture of four-seat practicality, with room for adults (the car is only a few millimetres shorter than a Polo) and rear seats that fold down. Much of the detailing will be watered down for production, but we wouldn't be surprised to see the touch screen remain, what with VW's fondness for them these days. Touché, VW.