In the past we’ve dug up a few interesting automotive brand names at the UK Intellectual Property Office – most makers tend to register a name as a trademark before it appears on any real car’s rump. But while we’ve been first to notice the odd curio, we’ve been less than reliable in our subsequent guesswork.

For example, when we highlighted that Vauxhall and Opel had registered the old Buick name “Electra” we thought that would be an ideal name for what actually ended up as the Ampera – the Euro version of the Chevy Volt. Some other bloggers liked our deductions and ran the same story – some even credited us.

We also thought that iStream might be a neat production name for Gordon Murray’s three-seat city car, the T25. And we were wrong again – iStream is the name of the T25’s minimalist production process. Two other names – iFrame and iCentre refer to, we think, the T25’s distinctive spaceframe-plus-sheet chassis (patent applied for) and flexible seating arrangements (ditto).

Still, not being right hasn’t stopped us digging. But it has stopped us guessing. So we will leave it as an exercise for the reader to determine what Gordon Murray is going to do with two new brands: iWheel and iLink.

OK, we can’t help ourselves. Guesses follow.

According to Autocar, the T25 will have a big door in its nose, to allow entry in the style of an Isetta bubble-car. So we think iWheel and iLink will be Murray’s patent-pending designs to allow the steering and pedals, respectively, to fold out of the way when the main hatch is opened.

Unless, of course, we’re wrong and they aren’t.

UK participants in the Mini E field trial may have had their new electric cars for just a week, but their rides are already obsolete.

BMW’s second testbed electric car, the ActiveE, appears substantially superior to the electric Mini. And not just because it is built around the larger, 1-Series Coupe body.

The electric Mini took its cues from the Tesla Roadster, using a large, boxy battery made up of thousands of small, cylindrical lithium-ion cells, hijacked en route to their usual homes inside laptops and camcorders. This weighty powerplant was then inserted in the centre of the wheelbase, and the humans and other accoutrements were squashed around it.

The ActiveE, in contrast, offers a layout that you might actually want to live with. It can carry four people and their suitcases, whereas the Mini E could carry two people and their sandwiches. Both cars need to spend substantial time hooked to a wall socket every 100 miles, of course (or, in the real world, about every 85 miles).

The batteries in the ActiveE are bespoke items, built with automotive applications in mind by SB LiMotive – a joint venture between Korean firm Samsung and German parts giant Bosch. Each cell in the new battery is bigger and squarer than those in the Mini E, and far fewer cells go to make up the battery. The cells are arranged into a T-shape, taking the place of a conventional engine, gearbox and prop-shaft, and filling the space beneath the rear benches.

And whereas the Mini E drives its front wheels, here the specially designed motor is integrated into the rear axle, delivering its 170bhp and 250Nm to the rear boots. This is sufficient to move the car’s 1,800kg bulk from zero to 62mph in less than nine seconds and on to a governed 90mph maximum. Having driven the Mini E, which is undoubtedly a quick and agile car, we have no doubts that the ActiveE will be equally eager.

Like the Mini E, the ActiveE is destined to go into limited production for a field trial with both private and commercial customers. No doubt participants will need to be committed to the cause – BMW is likely to levy a substantial monthly charge for taking part in the study.

Aston Martin has released pictures of its upcoming Cygnet city car, which is of course a Toyota iQ in fancy dress, tailored for owners of Aston sports cars.

The result is certainly a striking little car, even if it does put us more in mind of James Bond’s golf cart than a suitable form of transport for the image-conscious well-off.

Aston’s stylists have flexed their skills on the inside as well as the bodywork, and don’t seem to have known quite where to stop. While it’s always lovely to see hand-stitched hide take the place of elephant’s-arse plastic, we’re not so sure there isn’t too much lingerie-red leather. It all looks a mite like Plenty O’Toole’s boudoir.

And despite all the attention and expense lavished on the little thing, it still doesn’t seem to sport a centre armrest-cum-cubby-hole, which we found annoying by its absence when we took the unadorned base car – a Toyota iQ 1.33 CVT – for a spin a while back.

Real-world buyers will, of course, be able to specify a more subtle interior style when the Cygnet goes on sale in the UK and Europe at some ill-defined moment in 2010. Presumably most will choose options to match their existing Aston, since ownership of a full-size model is a prerequisite for purchase.

Aston’s ugly duckling has its detractors, many feeling it will sully the reputation of its bigger, swan-doored siblings. We beg to differ, and hope the plushest commuter car yet proves to be a soar-away success.

Greener cars can save you money at the pumps, and often in tax and insurance terms too, but which is the best financial bet when it comes to the fiercest motoring cost of all: depreciation?

We’ve spent some time sifting through the numbers offered by WhatCar.com’s depreciation calculator, to assess which are the winners and losers among two types of green cars: hybrids, and eco-diesels.

We looked at six models in total, and tried to choose six cars that might all end up on the same shortlist. All are practical family cars offering good interior space, and all cost roughly the same to buy. The cheapest car we looked at was the Honda Insight ES, with a base on-the-road price of £17,290, the most expensive the five-door Vauxhall Astra EcoFlex Active, coming in at £18,735 – about 8 per cent more.

Falling between these two fiscal goalposts were the ES-trim Honda Civic Hybrid, a Volkswagen Golf BlueMotion, a Ford Focus Econetic, and the cheapest (old shape) Toyota Prius – WhatCar’s data doesn’t yet cover the more expensive new Prius.

Residual value is a tricky thing to assess because it tends to depend on who you ask, but WhatCar’s numbers are estimates of trade-in value over time. Dealers do tend to lean heavily on this kind of “book price” data before sucking their teeth, shaking their heads, and telling you that nobody wants your old car. Perhaps surprisingly, on-the-road prices for brand new cars can be just as fluid, with most dealers willing to offer a substantial discount to those willing to bargain hard.

But even with all these uncertainties, graphs of value over time are still a good guide to how big a hole a car might burn in your pocket.

The first lesson to learn from the resulting graphs is that every car depreciates differently. Some, like the Vauxhall, drop like greased brick in year one and then, having shed a huge chunk of value, fall relatively slowly thereafter. Others, like the Prius and Insight, don’t exhibit the same hockey-stick plunge, instead losing value in a more linear fashion.

The shape of the line is absolutely key, because it shows that the amount lost to depreciation depends not so much on what car you choose, but when you buy it and how long you keep it.

For example, if you want to buy new and keep the car for three years, there’s no contest: buy a Prius. Opting for the Toyota instead of the Vauxhall will save you about £3,000 when you come to trade-in time – even the ever-popular Golf won’t do as well as the Prius. But if you plan to buy nearly new at 12 months’ old and to keep the car for the same three years, the Prius is the last car you should buy. Opting for a nearly-new Vauxhall instead of the techno Toyota will save you almost £4,000 over the three years.

A couple of other interesting points also drop out of the graphs. The three hybrids generally do better than the eco-diesels, with the best performing diesel – the Golf – doing only marginally better than the Insight – the worst performing hybrid – from new to year four. And also, it doesn’t really matter which hybrid you choose if you intend to buy new and keep for four years, as they all end up losing roughly the same amount, but it matters a lot if you buy at year one, at which point you should buy the Honda Civic.

So whichever green car you have your eye on, it pays to do your homework.

We’ll return to this topic shortly, looking at what to buy for a particular budget.

Honda says it has no plans to offer a production version of its newly unveiled Personal Neo Urban Transport concept (or P-NUT for fans of painful puns). This is just as well, for if it were to put a version on sale, no doubt it would swiftly hear from lawyers representing Gordon Murray.

The P-NUT explores many of the same avenues visited by Murray’s much-anticipated T25 city car, in the attempt to pack the maximum people into the minimum vehicle.

So exactly what do the two cars have in common?
Rear engine/motor? Check.
Three seats? Check.
Central driving position? Check.
Fold-away seats for versatility? Check.
Vertical rear hatch? Check.
Narrow nose and swooping screen pillars? Check.

Of course we don’t actually know exactly what production T25s will be like, assuming any are ever made, so there may also be marked differences between the two beasts. For example, it has been reported that the T25 will have a single, front-entry hatch for passenger access, whereas the P-NUT has two conventional doors.

Honda’s concept car is also a metre longer and half a metre wider than Murray’s midget, at 3.4m long and 1.75m wide.

For fans of Murray’s work, it’s a comfort to know that if the man himself can’t get his ideas onto the road, at least others think he’s onto something.