But we, who know how a sports car should be, want more. We want the Smart to be like a little Elise, albeit with the added civility already present in the Roadster which need not fog a real driving experience. There'll be the Brabus version, of course, all DaimlerChrysler-sanctioned and necessarily not as extreme as it could be. And then there's Digi-Tec.

Digi-Tec is German and, as its name suggests, it specialises in modifying the electronics that largely define how a modern car works. One of its chipped MINI Cooper Ss appeared in our recent tuned MINIs test (061), but it has also spent much time modifying Smarts. Now its British importer, Euro Sports Cars, which also brings us the Pagani Zonda, has devised its own package with the Digi-Tec engine upgrade, modified suspension, bigger wheels, some subtle but assertive bodily additions and a coat of black paint all over to finish it off.

All-over blackness. It's a kind of reverse irony; one of Smartness's essences is the contrasting 'Tridion' body frame peeping out from the coloured plastic panels all around, a way of advertising your free thinking to the world. So to have a mean, monotone Smart is to stand out from the Smart herd which itself stands out from the greater car herd. The body kit - sills, lower front corners, rear valance - is from that spoiler-provider of yore, Richard Grant, but is unique to Digi-Tec. 'They were brilliant,' says Euro Sports Cars' Mark Chittenden. 'They designed and built the kit from scratch in just seven days.'

Now, those electronics. More boost, and more fuel to satisfy the resultant increase in appetite, is achieved simply by altering the ECU's programming. But it's not a re-chip; instead there's a 'ghost' program which overlays the original one, and is undetectable by dealer diagnostics. So dealers and insurance companies need never know. Over to your conscience.

The result is a power rise from 80bhp to 112bhp, with a torque boost - now 118lb ft - to match. These are remarkable figures for an engine of just 698cc, but if these outputs were sent to the wheels via a gearbox with the standard car's lethargic shifts they would frustrate as much as excite. So bring on the next electronic enhancement: a gearchange speed livened up by 10 per cent. Sounds good; if only it was that simple. Oh yes, the top speed limiter is reset at 120mph instead of 112mph, too.

Other changes to help the Smart's new role as serious sports car concern the suspension and the brakes. Firmer dampers and shorter (but not stiffer) springs lower the ride height by a significant 30mm, and to cure the standard car's unsettlingly spongy, long-travel brakes we find grooved and dimpled front discs, and EBC carbonfibre-matrix brake pads. Wheels are 16in ten-spokers made in Italy to Digi-Tec's design; tyres are 205/45 R16 Bridgestone Potenzas.

Digi-Tec also played with the electric power steering, to improve the on-centre feel, but stopped when it was discovered that the lower ride height gives more negative camber, which itself sharpens feel and the turn-in.

Does it all work? Given the frightening ΂£19,250 asked for the Roadster Coupί¿½ (΂£18,450 for the Roadster roadster), we should hope so. Each body style will be replicated as a limited edition of 100 with all the additions you see here, although a much more bearable ΂£775 buys you just the engine and transmission tweakery for your existing Roadster. Strangely, though, you get 'just' 107bhp by this route.

Now, the proof. Start up, hear that three-cylinder thrum (amplified a little by a pair of larger tailpipes), into first, move off. Yes, feels perky as the turbo spins up. Flick gearshift paddle, into second, hear the wastegate whistle through the new, free-flowing, ram-fed air intake, re-press accelerator and - wait. Yes, the shift itself happened more quickly but what happens afterwards still leaves me tapping my fingers. There's no response from the accelerator until shortly after the clutch has finished its lengthy re-engagement, and with the extra boost the turbo lag is yet more obvious. As ever, the flow of motion is to be full of hiatuses.

Later, Chittenden will reveal the Smart range's fundamental gearshift problem. It is this: the rate of clutch engagement is the same regardless of which gears are being shifted between. So all shifts are saddled with the sloth of a clutch movement calibrated to move you off from rest. Digi-Tec is working on a more intelligent control regime, and we should pray for its success.

Anyway, I'm surge-pause-surging up through the six gears, progress occasionally further interrupted by a collision with the rev limiter. This happens because a triple never sounds as if it's revving anything like as hard as it really is, and what I have taken to be a stonking mid-range is actually a very keen up-range. Whatever, there's plenty of energy here and it's delivered with a deep, melodic tunefulness that is one of this car's greatest character assets.

As ever, you can drive around the gearchange issue and make tolerably smooth progress, although it's never as satisfying as a proper manual shift that you can control fully. But it's not all frustration; downchanges are a treat if you add a footful of revs-matching throttle (it doesn't blip the revs up enough on its own), and there's a fire to this Smart's pace that you don't quite get with the standard car. Digi-Tec claims 9.2sec to 62mph, so just think what this car could do if you could do a proper launch from standstill, upshift instantly and be back on the power straight away.

Perhaps then, too, we could really get the Roadster to dance through corners. The potential is there, for sure, and with these chassis mods you can feel a bite and a precision normally smothered in a power-steered Roadster. (They're better without power steering, but the public won't believe it.) Floor the throttle before an apex, to ensure power arrives when you need it, and you can feel the tail start to drift. You'll be pulling a surprising amount of lateral g before the ESP kicks in, discovering in the process that the harder you goad the Roadster, the better it gets.

There's one small downside to those springs and wheels, though. The extra offset causes quite a lot of bump-steer and camber-following, something a carmaker would try to engineer out but which, to those of us tuned into such things, makes the little sports car feel more alive. I don't mind it at all. And then there's the ride, firm but not uncomfortable, and the brakes, still too soft and springy. Maybe the planned rear disc conversion will fix that.

For now, this is as non-softcore a Smart Roadster as you can reasonably expect. Smart's chief engineer has admitted that it's not impossible to make a manual right-hand-drive Roadster because there's just enough room for a clutch pedal. OK, just do it.