The Japanese have always had a knack for miniaturisation, making ever smaller phones, computers and even hotel rooms. But one of the most extraordinary expressions of this ability comes in the form of the Kei-class city cars.

Under Japanese laws, cars less than 4ft 10in wide and no more than 11ft 2in long benefit from reduced taxation and insurance costs and are exempt from the need for city-dwelling owners to prove they have adequate parking facilities.

With no such benefits on offer to British buyers, the often strangely styled Kei cars have appealed only to a handful of enthusiasts; that is, until the arrival of the Daihatsu Copen at the end of 2003.

Based on a shortened Daihatsu Cuore platform, it instantly became the UK’s smallest and cheapest two-seater sports car, retailing at just £13,000. Despite the diminutive price tag, the Copen boasted a folding metal hard top in the style of a Mercedes-Benz SLK, alloy wheels, air-conditioning and a turbo.

But before you rush out to buy one in the expectation of vivid performance, it is important to note that another criterion of the Japanese Kei-class cars was that engines should be limited to just 660cc, and despite the inclusion of a (tiny) turbocharger, the Daihatsu’s engine produces only 67bhp. But what it lacks in grunt it makes up for in spirit. The motor revs to a giddy 8000rpm, and thanks to a kerb weight of just 1,814lb the Copen will reach 60mph from standstill in a respectable 11.7sec, and top out at 106mph.

With the electric folding hard top stowed safely in the boot, access to the cabin is pretty good. The doors are surprisingly wide, and once you’re inside, the seats are also of reasonable size. The smallish steering wheel ensures your knuckles don’t brush on the door panels, and the good range of movement fore and aft ensures the tallest drivers have decent headroom. Only when you try to accommodate a couple of hefty chaps does the car’s lack of width become apparent, driver and passenger tessellating into place.

With the folding hard top in situ, it becomes a challenge to make an elegant exit from the Copen, the smaller frame of the average Japanese owner being better suited to the task than the burlier chassis of a northern European.

On the road the Copen feels like a very refined go-kart, its sharp steering and eager engine making it easy to thread through the traffic. Push the car hard and its tyres will squeal with pleasure, finally giving way to understeer. The keen-revving engine makes 30mph progress feel like 50mph, and 50mph more like 70mph – no bad thing if you’re after driving thrills but appreciate the value of your licence.

Ride comfort is pretty good on smooth tarmac but gets jiggly on poor surfaces due to the little car’s short wheelbase. Clearly designed for city use, the Copen’s short-ratio manual gearbox is perfectly suited for zipping around town, but feels short-legged at motorway speeds, although the crisp gearchanges are always a delight.

With the roof up, the cabin feels a little cramped, although it at least liberates some boot space. The boot, at 210 litres, is on a par with more traditional hatchback superminis for capacity. But it’s a different story with the roof stored, for then, with less than 20 litres of luggage space remaining, it’s a matter of bringing with you only what you can store by your passenger’s feet.

While a used Copen may not feel as solid as a German car, there is every chance it will keep going for just as long, provided it is well maintained. But keeping that free-revving engine running on fresh oil is essential, and for higher-mileage users, the 3,000-mile oil-change interval becomes a necessary bore.

Secondhand Copens aren’t plentiful, despite which they don’t command rarity value. Yet. A three-year-old example will cost around £6,500 – barely half the new price – and 2008 promises the prospect of the first sub£6,000 examples on the market. Happy hunting.

Alloy wheels Standard on all models but check rims for signs of kerbing

Engine Original 659cc turbocharged engine replaced by a nonturbo 1298cc unit during 2007, a move that also brought a drop in price

Stereo Standard unit is fiddly and barely loud enough to hear with the roof down

Interior Leather upholstery a desirable and popular option that commands a £300 premium on used-car market

Air-conditioning Comes as standard on all models

Roof Electric folding metal roof takes just 25sec to fold away

Safety Twin front airbags, antilock braking and brakeforce distribution are standard, but Euro NCAP crash testing hasn’t been carried out due to low production numbers

Boot The 210-litre boot is pretty good when the roof is up, but dwindles to almost nothing when the roof panel is stowed

Servicing Oil changes due every 3,000 miles. Later nonturbo cars need servicing only every 9,000 miles

Insurance Relatively high group 9 insurance

Front bumper Check lower edge, which is easily scuffed on speed bumps

Vital statistics

Model Daihatsu Copen
Engine 659cc, four cylinders
Power 67bhp
Transmission Five-speed manual
Fuel consumption 44.1mpg (combined)
Acceleration 0-60mph: 11.7sec
Top speed 106mph
CO2emissions 151g/km
Road tax band D (£140 a year)
Cost new today £11,495
The one to buy 2005 05 with 20,000 miles. Pay £7,725 at a Daihatsu dealer, or £7,000 privately

Values

Mileage 10,000 20,000 40,000
2004 04
Trade £5,975 £5,650 £4,975
Retail £7,475 £7,150 £6,475

2005 05
Trade £6,600 £6,225 £5,475
Retail £8,095 £7,725 £6,975

2006 06
Trade £7,275 £6,850 £6,050
Retail £8,775 £8,350 £7,550

Or for similar money

2005 05 Mazda MX-5 convertible 1.6i 2005 05 Peugeot 206CC 1.6 Sport 2006 06 Ford StreetKa 1.6i 2006 06 Smart Roadster automatic 2007 07 Citroën C3 Pluriel 1.4i

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