Loosely based on the John Cooper Works (JCW) Challenge car, these are essentially Cooper S vehicles with a higher-output engine; a low-back-pressure exhaust system; a stiffer sport suspension; 17-inch light alloy rims with low-profile, performance tyres; Brembo performance brakes; and BMW's dynamic stability control (DSC) and Dynamic Traction control system (DTC) with Electronic Differential Lock Control (EDLC) as standard equipment. All JCW models are only available with a specific Getrag 6-speed manual transmission, and come with distinctive "John Cooper Works" badging in place of the normal "Cooper S" badging. The JCW vehicles are also factory-built, which further distinguishes them from earlier Mk II Cooper S models with any of the available John Cooper Works accessories (engine and suspension upgrades, aerodynamics kit, etc.) that are dealer-installed. All JCW models achieve the same EPA fuel economy ratings as their Cooper S counterparts.

The engine is rated at 211 PS (155 kW; 208 hp) and 261 N⋅m (193 lb⋅ft); under heavy acceleration, the engine automatically boosts torque output to a peak of 279 N⋅m (206 lb⋅ft). These figures are achieved by reducing compression ratio to 10.0:1, and increasing boost from 0.9 bar (13 psi) to 1.3 bar (19 psi) when compared to the turbocharged engine used in the Cooper S. According to Mini, the JCW Hardtop will sprint to 97 km/h (60 mph) in 6.2 seconds, with the JCW Clubman clocking in at 6.5 seconds; both vehicles top out at 237 km/h (147 mph)

The JCW variants were unveiled in 2008 at the Geneva Auto Show, as 2009 model-year vehicles

This car is unmodified and in good condition with a substantial service history. We have replaced the turbo oil feed pipe which is the cause of oil leaks in the Cooper S. This is a substantial job which now ensures that this car will be leak free for years to come. We have also refurbished the wheels and will be replacing the front tyres.

All JCWs come with Sat Nav (we have updated to the latest maps), leather seats, xenon headlights and a fabulous panoramic roof.