What is it?
A hugely accomplished super-saloon and a worthy addition to the annals of the M5.
By super-saloon standards this M5 is beautifully balanced and pliable. The brakes have their work cut out, but the chassis works both ends evenly: you can dive into corners with confidence and come out the far side knowing how much you can open the throttle before the rear end starts to send itself sideways. A hint of warning though: don't turn off the traction control unless you have a lot of space to play with.
Despite the acceleration it delivers and the speed it carries, this is not a raw, animalistic car, even with all the buttons turned up to 11. The standard 5-Series is a big, heavy, insulating machine and the M5 is the same. It can't quite shed that cosseting feeling: this is an M5 that's aimed primarily at businessmen who like driving, rather than drivers who do the business.
Purists might scoff that the mighty M Division has eschewed the traditional high-revving, naturally aspirated V10 of old for a twin-turbocharged V8. But this is no ordinary forced induction powerplant: with 552bhp and 501lb ft of torque it is the most powerful M car ever. And a 0-62mph time of 4.4 seconds, a 0-124mph time of 13.4 seconds and a top speed of 190mph is nothing to scoff at. Unless you're in the passenger seat, of course.
On the inside
No doubt we'll see a Touring version soon enough, but unless you have livestock, there's not much need to stray from a saloon. The M5 is as big and comfy as any other 5-Series.
Mid 20s mpg if you're careful, around 10mpg if you're not - this isn't a Smart. But look at what you do get for £73k. Marvellous.