The BMW M6 Cabriolet has been spotted testing on and off in the last couple of months. This week, our spy caught the M6 Coupé being tested alongside the drop-top. Although it’s going to be at least a year before the new model hits assembly lines, the sparsely camouflaged Coupé reveals some significant changes. Apart from the quad exhaust pipes, the M6 Coupé also seems to have received new front and rear bumpers as well as side skirts. In addition to improving aerodynamics, these also help to give the M6 a sleeker look than the base models. As for the powertrain, the new M6 is expected to pack the same turbocharged 4.4-litre V8 that powers the recently revealed F10 M5, which will produce up to 592bhp.