[The Automotive Enthusiast]

Like it or not, the next BMW M5 is essentially guaranteed to be all-wheel drive. Traction control, stability control, and torque vectoring can do a lot to help put rear-drive power down safely, but M division's CEO Frank van Meel has already admitted that a move to rear-biased AWD is inevitable in the BMW super-sedan. The good news is, the next M5, shown above in a spy photo, might offer a button to switch back to rear-wheel-drive on demand.
According to German-language magazine Bimmertoday (as translated by BMWBlog), owners of the next-gen M5 will be able to switch to rear-drive by selecting the appropriate drive mode. You'll still be lugging around the weight of the AWD system, but at least tail-happy shenanigans will be available at the push of a button.

Similarly, the 2018 Mercedes-AMG E63 S is now all-wheel drive?but in Race mode, drivers can pull both paddle shifters to completely disconnect the front axle for rear-drive hilarity.

Considering the acceleration and all-weather traction improvements, we understand why BMW would want to give the next M5 all-wheel-drive. But we have to admit, we like the idea of being able to turn the new M5 into a 600-horsepower drift missile any time we get it onto a track.

http://www.roadandtrack.com/new-cars...r-wheel-drive/