Here at evo we don't necessarily share Mr Mainstream's view of car-sense, but at ΂£12,410 for the Smart City Coupé Brabus and ΂£14,210 for the Smart City Cabrio Brabus, notions of sensibleness take a battering even for those seeking an experience outside mundanity's envelope. For that sort of money, the Brabusisation package had better be pretty special.

We've had Brabus Smarts before, of course, some of them chipped-up to a heady 84bhp or so with tiresome speed-limiters disarmed, wheels fattened and every chance of tumbling down a blowy motorway like a tumbleweed.

But this is different, because there's now an official Smart-Brabus joint venture, much like that between Mercedes and AMG. That doesn't stop Brabus from continuing to soup-up other DaimlerChrysler products in its own way, however; as we toured the Brabus facility at Bottrop, near Dusseldorf, we saw a Brabus SL55 AMG nearing completion. 'Oh God, the brand corruption,' wailed a senior DaimlerChrysler PR.

This latest Smart Brabus is an official part of the range, above Pure, Pulse and Passion. Shouldn't it be smart&BRABUS, then? It uses the larger, 698cc engine from the new Roadster, but here it delivers 75bhp instead of 82 because the exhaust system is squashed into a smaller space. Claimed maximum speed rises to a limited 93mph from 87, with fatter wheels to help give the required high(ish)-speed stability. The front tyres are now 175/50 R16, with 205/45R16 on the back. Suspension and steering remain standard.

Naturally, the Brabus is visually toughened-up with a deep front spoiler, side skirts, a Brabus-specific front grille and a new heat-shield over the also-new twin-pipe exhaust.

Inside we find all the top Smart options plus heated leather seats, a leather-rim steering wheel, carbonfibre-look instrument cowls, holed aluminium pedals and an aluminium handbrake handle with a Brabus logo. Does all that justify the price, given that you haven't had to pay for the lesser original parts as well? At least it's better value than the Crossblade, the ultimate pay-more, get-less car (no doors or windscreen, remember?).
We set off from Bottrop in a posse of tiny tearaways, a smouldering of Smarts. The steering may be standard but it feels keener, or at least less sneeze-factor slow (don't you just hate product-liability killjoy laws?). That's the wider rubber making its presence felt.

The bigger engine's extra torque makes it easier for Smart to program quicker, cleaner shifts from the sequential 'Softip' clutchless transmission, and with practice it's possible to get entirely smooth gearchanges with little more effort than you'd expend with a normal manual. Certainly it's the best Smart transmission I've yet tried; Brabus boss Bodo Buschmann says he used to wish a Smart could have a regular clutch and gearstick, but he's happy now.

We're squirting through traffic with an energy alien to a regular Smart, and now there's a tunnel so we drop the windows. As its note echoes around the tunnel walls, the three-cylinder turbo engine sounds fantastic through its new exhaust, deep and crisp and yes, a little 911-like. This is fun. Really.

Now we're on an autobahn. It's a new experience, for me at least, to drive a Smart (Roadster excepted) which doesn't get in the way of traffic at speed. It mixes it with the masses, a 0-62mph time of 12.3 seconds suggesting sufficient energy to match most real-world flow rates. The steering, for all its extra crispness, still feels more lethargic than it needs to, though. 'We'll make a quicker rack if there's demand,' claims Buschmann.

This lethargy is highlighted along some twisty backroads, where it's clear that understeer is still compulsory to protect ourselves from ourselves. But at least the front wheels hang on longer before washing wide now; within its play-safe, DaimlerChrysler-mandated constraints, the Brabus does show flashes of sportiness.

What's more, it's fully capable of attracting a speeding ticket, as I discovered when laser-zapped at 42mph on a wide, empty road with, unaccountably, a 31mph limit. Strangely, it merely added to the fun of the day.