BMW M5

It may weigh three times as much as the German manufacturer's F1 flier, and have five seats instead of the one, but the flagship M car and the latest BMW Williams racer still have plenty in common. A 90-degree V10 engine, for starters, with a seven-speed sequential manual gearbox to follow, and a seriously sophisticated launch control.

But does it all work? You bet it does. This 507bhp supersaloon goes as fast and sounds as good as you can imagine, and then some. The performance is simply unbelievable, but unfortunately - in case you hadn't guessed - so is the fuel economy. It's just as well, then, that at the touch of a button you can run the motor in 400bhp tune. BMW claims that in derestricted mode, the engine could power five occupants comfortably past 200mph. Yet given the refined nature of the M5, you would probably feel as though you were cruising on the inside lane of a motorway.

Keeping all this muscle in check is a quick-witted stability control system which, when set to MDrive from the steering wheel control, gives more room for driver error. Turn it off and you will need your wits about you, or you may end up in a wall, as Ralf Schumacher did in his Williams in July's US GP.

Of all the power-crazed four-doors around, this one feels by far and away the most capable of putting all its pot-ency to good use, with sharp handling and taut body composure from the Electronic Damping Control system.

More gadgets come in the form of a head-up display for speed and revs or sat-nav, plus adaptive headlamps which turn with the steering wheel. No doubt about it, after our first drive of the fastest BMW ever produced, the maker of the 'ultimate driving machine' has clearly raised the stakes once again.