Spied: 2013 BMW M6 Convertible

The BMW M6 Convertible has been spied testing ahead of its debut at theGeneva Motor Shownext month.The 552bhp soft-top is the most powerful production BMW ever built, and takes the 650i M Sport – which at £77,715 already costs £4,675 more than an M5 – and sharpens it up.These photos reveal that the Convertible will follow the formula established by the M6 Coupe and Gran Coupe stablemates, which