Sales might have slowed for Mercedes Benz over the past year, but the product just keeps getting faster.

Here in time for Christmas is the mighty E63 AMG, a $243,900 rocketship capable of embarrassing numerous supposedly more focussed two-seater street racers of greater pedigree.

With the luxury sector having born the brunt of the new car sales slump, it's no surprise that Mercedes sales have softened over the past 23 months.

Yet with customers already having spoken for half of the dozen examples of the most electrifying E, it seems homes can still be found for the big money models.

Mercedes Benz New Zealand marketing manager Coby Duggan says the year actually hasn't been too bad, all things considered.

He's anticipating achieving 900 registrations in 2009, which is a positive comeback over last year's 809, a decade low-point.

While a return to the period of 1000-plus registrations experienced from 2003 to 2007 is thought unlikely to occur before 2011, the high-end market is still active.

He says the mainstream E-Class models have launched positively and interest in the hard-core AMG product has remained surprisingly strong. Even during the period of greatest gloom, AMGs continued to contribute a steady 10-12 percent of total sales volume.

How many E63s ultimately get here in 2010 is yet undecided. "At the moment we're reasonably comfortable with production allocation (16 units), but we'll just continue to keep an eye on customer demand.

"As I said, AMG demand has remained relatively stable. In fact, the cars at the top end of our range have held up pretty well over the past year - we've seen some pretty heavy metal delivered."

While the E63 costs plenty of moolah, it has the mumbo to make that outlay worthwhile.

At the core of its appeal is that venerable but still rightly venerated 6.3-litre V8 engine.

Producing a soundtrack you're unlikely to ever tire of, it bangs out an enormous 386kW and 630Nm of torque. This means the sprint from 0-100kmh takes only 4.5 seconds, even though the car weighs 1840kg.

The unit is mated to a seven-speed automatic gearbox with four driving modes: comfort, sport, sport plus and manual. Slick gearshifts are promised by the electronic settings, from 250 milliseconds in comfort to a right-to-the-redline snap shift in 100 milliseconds in sport plus.

That performance sprint time to the legal highway limit is just 0.1s off the claimed pace of the smaller C63, which still the country's most popular AMG model - though the bigfoot ML63 is close behind. It's also enough to frighten many supposedly more hard-edged two-seater street racers.

The AMG sedans hold bragging rights as the specialist tuner's fastest wares here, but only until mid-2010. That's when Mercedes lands the first examples of the incredible SLS AMG - the half million dollar modern rendition of the famous 1950s 'gullwing' sportscar.

Still, the E63 will always be the more practical and most capacious choice. It is capable of more than 300kmh, though an electronic restrictor pegs it to 250kmh, and like the SLS gets a setting called "RS", for race start, which is a Formula One-style launch control system.

I suppose another of the attractions is that it looks obviously aggressive but like the C63, not overly so. The styling tweaks run out after 19-inch alloy wheels, a small lip spoiler and some extra flares here and there. It looks angry, yes, but not necessarily like it's about to eat a Porsche Boxster for breakfast. Even though it can.

The bodywork is a mere covering for a heap of interesting technology. Given that the standard E-Class is a rather high-tech device, the AMG crew has been able to get on with the jobs they're really good at. Namely, in addition to pumping up the power, they've also fine-tuned the suspension.

Actually, forget finetuned. This is a seriously rework of the standard car. The E63 gets an entirely new front axle with a 2.2-inch-wider track. Spring rates are twice as stiff as the regular car's, necessitating a change from air springs to conventional coils.

Load-leveling air springs remain at the rear. In addition, the anti-roll bars and the subframe bushings have been beefed up. The steering ratio, at 14.0:1, is 22 percent quicker than in the regular E-class and uses a direct, rather than variable, rack.

And that's actually phase one. An optional performance package stiffens up the front anti-roll bar and the tuning on the standard adaptive dampers, adds lighter forged alloy wheels, but keeps the 'standard' 255 section front and 285 rear rubber.

More upspend opportunity comes with the brakes. Massive calipers can be teamed with optional carbon ceramic discs that can handle race track punishment.

A big wallop makes for a big thirst, of course, and while Benz reckons improvements to fuel consumption of 12 percent make it frugal among peers, the claimed average of 12.6 litres per 100km is not exactly going make it Greenpeace car of the year.

Interior enhancements include a thicker steering wheel with paddle shifters, alloy pedals and heavily bolstered seats.

Next to gear shifter are buttons to sort the transmission mode, the stability control settings and a suspension adjustment that chooses between a compliant ride - by AMG standards - and a much firmer setting with better body control.

What this means to you: The greatest of Es.