Ever since BMW revealed a thinly-disguised concept M5 at the Shanghai show we've been quietly obsessing over the forthcoming super-saloon.
The outgoing car is powered by BMW's titanic 500bhp 5.0-litre V10 and is more desirable than Megan Fox holding a bacon sandwich. However the new car will dispense with naturally aspirated heaven in favour of the manufacturer's 4.4-litre turbocharged V8.
Word is that power is pushed beyond 560bhp, but will forced induction rob the hallowed M car of its unique charm? We'll have to wait until the Frankfurt show in September to find out - until then, here's the just-released video of the challenger in training.