Have a look through those wheels, too. Gleaming behind the elegant spokes are some pretty sizeable brakes. With discs that big, it's clear that this is a car that'll take a lot of stopping, so it must have a lot of go. Quite what that 'go' will be we can't yet be sure. Under the bonnet of the show car was a 265bhp 3.0-litre six-cylinder engine, but American magazine Autoweek says that the M-coupe will use the 3.2-litre engine from the M3, uprated from 343 to 360bhp. In the end, though, what really makes us sure that the car in our shots is an M-coupe are the front and back ends. At the front, the air dam is filled with a sporting honeycomb mesh and its pronounced lip is even more aggressive than the showcar's. Likewise, at the back, where the existing Z4 roadster has just one pair of tailpipes (as does the Z4 coupe showcar), the coupe we spied has a pair of distinctly sporty twin exhaust pipes, just like an M3 and M5.