Back in 2011 our spy photographers caught Mini’s new Cooper set for release in 2013. Now they'v captured the new S version undergoing testing alongside the BMW 1 Series GT.The Cooper S in our spy images is heavily camouflaged though it appears slightly longer and wider than the current model. NEW ENGINESThe new model adopts a smaller grille, longer hood and slimmer A-pillars. The bonnet-mounted air-intake of the Cooper S is covered on this prototype.The British automaker has some major changes planned for the interior. Mini will ditch the centre-mounted speedometer for a more traditional instrument cluster as well as many trim changes they’re reluctant to give more information on.Engine options remain a bit of a mystery, but we wouldn't be surprised if entry-level models are equipped with the new three-cylinder TwinPower engines. For the Cooper S, however, a new turbocharged 134kW 1.6-litre petrol likely while the JCW will receive a similar unit capable of 164kW.