These spy shots show what looks mostly like a JCW MINI Coupe in testing, but with a new rear diffuser wrapped in camo. If this is in fact the GP edition of the JCW Coupe, it could receive similar modifications to the GP II edition of the standard JCW Cooper.
Those modifications include extensive weight-savings measures, with a carbon fiber roof, carbon fiber side mirrors, a more spartan interior, and other lightweight materials. A more race-tuned suspension, better aerodynamics, a potent tune on the turbo engine--likely around 215 horsepower--and, of course, since we're talking about MINI, unique graphics and badges.
As of yet the MINI JCW Coupe GP is still in very early testing stages, but we'll keep you posted as the project develops. The 2012 MINI Cooper GP II saw 2,000 units built worldwide, with just 415 of those coming to the U.S., so even when it is finished, don't expect to see these punchy little coupes everywhere.