Spy shots show massive brake discs with M badging. The BMW M6 Cabrio will share an engine with the upcoming F10 M5.

Here are the latest spy shots of the upcoming BMW M6 Cabriolet, spotted while doing some testing in the colds of Scandinavia close to the arctic circle.

This prototype here is still rather heavily camouflaged but we do get a close look at those massive brake discs with the M badge clearly visible on the shot of the rear wheel. Our spy photographers report that this prototype still isn't fitted with the proper bumpers so we're not sure how far along in development the M6 Cabrio really is.

What we can be pretty sure of is that the M6 will share a power plant with the upcoming F10 M5. That would be the 4.4 liter twin-turbo V8 with an output of around 600 PS (592 bhp / 441 kW).

The BMW M6 Cabriolet is expected to debut sometime next year.

Gallery: 2012 BMW M6 Cabrio spied in the cold