It's a measure of the M5's sheer drivability that 500bhp does not feel like a handful. The engine picks up rapidly from below 2000rpm, aided by the gearbox's seven close ratios. It will rev to 8250rpm, but the mid-range power makes it unnecessary to stray that far.

The beautifully balanced chassis puts you at ease, while the steering and brakes are just as good. The M5's stunning traction, grip and feedback will almost take your breath away on dry roads, and the ride is civilised on smooth main routes. However, the 19-inch wheels and low-profile tyres don't take kindly to potholes.

The V10 howls at passers-by and growls at its occupants, but it's a sound you'll actively encourage at times. There's not much disturbance at cruising speeds, but the big tyres can kick up road noise on some surfaces. Gearshifts can also be jerky in the most aggressive manual programmes and slurred in the automatic modes, but with a bit of practice the process becomes smooth.

The M5 will cost plenty to run in everyday motoring, and you don't even have the prospect of especially strong resale values to look forward to. You won't get much of a discount when you're buying, either, and you'll be lucky if your fuel economy is better than mid-teens in everyday motoring. To cap it all, it's in the top bands for company car tax and insurance.

As with any 5 Series, care and attention ooze from every joint and fixing of the M5. This careful approach is also evident in the cabin, where top-notch materials are used and put together to make a hugely appealing interior. With proven mechanicals, reliability shouldn't be an issue.

Safety features are comprehensive, with eight airbags, anti-lock brakes, stability control and even an electronic differential lock to help keep the car from sliding off the road. BMW security is effective, too. Even if thieves break in, they will be hard-pressed to drive the car away.

As with any other 5 Series, the M5 is spacious, refined and comfortable, but it also has the benefit of a head-up display to help keep your eyes on the road. However, on top of the iDrive system to control the stereo, sat-nav and so on, the extra variables will take time to get used to. For instance, you can even set-up the car to vary the support of the seat's side bolsters according to how much the steering wheel is turned.

In the back and the boot, the M5 is just like any other 5 Series Touring. This is a roomy car for four (the transmission tunnel rules out five unless one is a small child) and the boot is big enough for business or sports paraphernalia or a family's holiday luggage. The Touring model scores over the saloon with its bigger boot, and the only slight complaint is that the rear seats don't fold down completely flat.

As befits the flagship of an executive car range, the M5 comes with a generous specification. You get the head-up information display, a navigation system, leather seats and bi-xenon lamps as standard, while Bluetooth, a digital TV and seats with variable side support are among the options.