The front suspension gets uprated springs and dampers, strengthened and lightened supports and wishbones, new tube-shaped anti-roll bars, lightweight support bearings and triple-path strut mounts. The multi-link rear suspension has also been lightened and toughened up.
Drive finds its way to the front wheels via a ‘split’ system of driveshafts, in which an intermediate propshaft running underneath the engine allows for the fitment of equal-length halfshafts for each driven wheel – and more consistent steering feedback as a result. Braking is by 330mm Brembo discs and four-piston calipers up front, and wheels are 17in alloys as standard, with 18s available as an option.
Beside that choice of bigger wheels, variable damper control is the most dynamically influential option on the car. These substitute the standard passive shocks for twin-reservoir switchable units which can be firmed up using the car’s Sport drive mode. Our test car had them fitted.
It certainly looks the part. One of BMW’s mission statements was to give the JCW more notional clear air in which to breathe alongside the lesser Cooper S, and so the more aggressive looks are just as important as the more purposeful mechanicals and extra grunt.
The enlarged mesh radiator grille sits between standard LED headlights that make for an assertive presence in your rear-view mirror, and nearer the asphalt the front foglights have been junked in favour of extra cold air ducting.
The optional part-leather bucket seats of our test car were grippy and broad, although their squabs were a bit flat. Mini’s interior makeover for the JCW is otherwise effective, if a little simplistic: lots of white chequered detailing on black plastic trim, with red highlights.
As for the rest of the standard equipment - there is an aggressive body kit, rear spoiler, DAB radio, Bluetooth and USB connectivity, cruise control and sports suspension. As for adding extra luxuries to the JCW, you can opt for the Chili pack which adds climate control, velour floor mats and automatic wipers and lights, while those pining for sat nav will need to tick the Media pack box, while parking sensors, a reversing camera and a Harman & Kardon stereo are bundle in the Tech Pack.
To drive, the JCW is indeed surprisingly fast up to the legal limit and flexible enough in real-world use to keep up with any lower-order sports car – and any hot hatch up to, say, a Mercedes-Benz A45 AMG. The engine responds keenly, with gutsy low-end torque, a gravelly, crackling exhaust note and ample freedom at high revs.
Our test cars were automatics because autos were the first batch off the Cowley production line, but 80 percent of UK cars are expected to be manuals. For what it’s worth, the auto shifts smartly in manual mode and locks up quickly at low revs, but it’s a bit too keen on unnecessary downshifts under acceleration when left in ‘D’. The manual 'box is slick and smooth to shift gears, although it can seem slightly weighty and notchy when trying to slip through the six-speeder quickly.
Handling is predictably direct, hyperactive and excitable, if a little less highly strung than that of its predecessors. The idea of a becalmed Mini JCW may sound a bit confusing – like a kleptomaniac with a conscience, perhaps – and understandably so.
Like every fast Mini since BMW’s acquisition of the brand, this one is much happier scything along smooth A-roads than it is pitching and bobbing, staccato-style, down a rough country lane. But it dives into those smooth apexes with instinctive zeal and responds to every input as if on a hair trigger.