Mercedes CL600

Also significant are two big numbers, 500 and 800. The former is the car's bhp - an incredible 36 per cent more than in the previous CL600's 12-pot engine. The latter is the Nm of torque - increased by more than 50 per cent. These are huge upgrades, but can the CL handle them?

It's no surprise this car is rocket quick - it will hit 60mph in a fraction less than five seconds, and won't stop accelerating hard until you reach the electronic limiter at 155mph. But the thing you first notice when you take to the road is how smoothly the CL lays down the power. Delivery is instant, and leaves you confident enough to overtake in places you know anything less than a supercar would struggle.

A gentle squeeze of the right pedal sees the Merc accelerate from 30mph to 70mph - the key overtaking band - in the blink of an eye. But it's not only about straight line speed. Grip through the corners is excellent, even in the wet, and the steering is alert, offering keener drivers plenty of feedback. Importantly, the huge brakes - visible through the new alloys - are powerful and do the job with minimum fuss.

Surprisingly, Mercedes hasn't given the car Pre-Safe, the firm's innovative system which senses there's about to be a crash and prepares the vehicle for impact. The set-up is now standard on the revised S-Class, yet wasn't considered for the coupί¿½. When we quizzed the company's engineers why Pre-Safe wasn't included, they merely looked awkward and changed the subject...

The designers still have plenty to be proud of, though. Considering the amount of power on tap, the CL600 is not difficult to drive, and it averages an impressive 19.2mpg, too. And as well as being a real thriller, you can push it hard, confident that it's unlikely to jump up and bite you. For the lucky people who buy CLs and run them as everyday cars, that's a reassuring quality.