Now that the wraps have come Gordon Murray’s revolutionary T25 city car (we scooped it undergoing road trials today) I thought the great man might not mind if I cold-called at his Guildford design HQ, south-west of London, seeking a few more details.

Reception for the car’s shape and concept has been both strong and positive, many people using the word “funky” for the cute and revolutionary styling. However, what nobody understood - because our hastily-snatched picture failed to explain it - was exactly how the T25’s one-piece door worked. If I asked nicely, would Gordon show me?

See Autocar's exclusive Gordon Murray T25 pictures, including the radical 'door' in operation

The answer was yes. I was smuggled into the workshops (where several other fascinating projects were shrouded by hack-proof dust-covers) and shown, in the flesh, the same T25 prototype our cameraman had seen.

First impressions: it’s tiny, but its stance, height and the clever resolution of its distinctive styling give it an impressive presence. That’s good. The last thing you want is for your tiny car to seem toy-like, and the T25 doesn’t.

The door is a typical example of Murray being brilliantly simple, other examples of which are visible all over the car. A large, rigid assembly comprising the windscreen, the side windows and side panels and much of the roof, all swings forward with BMW-like precision to present a low-sided cockpit into which all three occupants can step into with ease and convenience.

The cabin cover - it’s not enough to call it a door - is gas strut powered. You open it by pressing a button on your keyfob remote as you approach the car. When the car is tightly parked against others, access is far more dignified than for any conventional car. Closing the cockpit cover is easy: it’s part-supported by gas struts, but gravity helps you pull it down until it’s nearly closed, when a soft-closing mechanism takes over and pulls it securely against rubber seals.

Sitting for the first time in the T25’s central driving seat, two things struck me. First was the unique appeal of a symmetrical vehicle, which only the motorcyclist - or the driver of a McLaren F1 or single-seat racing car - has been able to know until now.

Second was a feeling of value: it was hard to believe that the target price of this car is below £7000. The unique cockpit (into which Murray admits he has tried to introduce echoes of the McLaren F1!), plus equipment like the paddle-shifts, the push-button transmission controls, the unique instrumentation and the soft-closing electric door, combine to give the car a special distinction.

As I said when trying the bodyless ‘mule’ last year, this is a car people will want for many more reasons than its main event, the economy of build and operation.

We are looking at a motoring phenomenon that could eventually have the impact of Issigonis’s original Mini, 51 years ago.