BMW has revealed its all-new M6 Gran Coupe at a small event at the Nurburgring, and we've got the first images. The four-door super-coupe is set to be officially unveiled online next month ahead of its live debut at the 2013 Detroit Auto Show in January. The pinnacle of the 6 Series features all the hallmarks of an M model, including beefier bumpers and side skirts, a carbon-fiber roof, a quad tailpipes and 20-inch wheels. Expect the same 4.4-liter twin-turbo V8 that powers the M6 to carry over with its 553 hp and 501 lb-ft of torque.