If you drive a big 4x4, chances are you may have received some negative feedback from some sanctimonious road users on your choice of car. You can either ignore them, buy something a little less obtrusive or alternatively, earn so much money that you move into a class where normal rules do not apply. If that's the case, you may well need a Mercedes ML63 AMG.

A key priority amongst buyers of very high end houses these days is the ability to drive into a vast garage and not be able to be seen from the road. This way celebrities and high profile business people can always retain a certain amount of privacy. This is the world inhabited by ML63 AMG owners. It's not your normal kind of luxury 4x4. 510bhp sees to that. So does the £75,000 price tag.

Yes, you did read that last figure right. What's more, that power output is achieved without recourse to anything as simple as turbocharging, Mercedes claiming that at the time of launch, this was the most powerful normally aspirated V8 engine in any production car. The ML63 wears its superlatives comfortably. It outguns the Porsche Cayenne Turbo and the BMW X5 4.8iS in terms of sheer power and due to the fact that its chassis is comfortably lighter, it's crushingly quicker as well.

The fact that this engine reaches its peak power output at a heady 6,800rpm should speak volumes. This is no lugger. Under the bonnet of this M-Class beats the heart of a supercar; a hand built 6.3-litre engine that thrives on revs. Even the peak torque figure of 465lb/ft is reached at a lofty 5,200rpm. If your driving style is to expect huge expanses of low-end grunt, this Mercedes isn't for you. A Volkswagen Touareg V10 TDI will probably be more the ticket. If, on the other hand, you'd like to experience the somewhat unlikely scenario of a full-sized 4x4 that thinks it's a hot hatch, the Mercedes will paint a huge grin on your face.

Like many series production Mercedes models, the top speed of the ML63 AMG is limited to 155mph. This means that in theory you won't storm the autobahns any quicker than the driver of a humble C350 but this sort of money buys the ability to have the technical bods at Affalterbach slyly noble a couple of lines of the ECU's coding. Despite the ML's huge frontal area, you'll then be looking at a top end that's on nodding acquaintance with 180mph. Of possibly a little more relevance to many will be the car's ability to step off the line cleanly. Paparazzi will need handy motorbikes to stay with the ML 63 AMG's sprint to 60mph of just 5.0 seconds. If they're trying to keep pace in a Porsche 911 Carrera, they'll be treated to the sight of the Mercedes' quad tail pipes pulling away from them.

"The ML63 AMG offers an unlikely brand of 'instant-on' shocking acceleration"

What's more, whereas you'll need a fair degree of skill to extract a five second sprint to 60mph from a 911, in the ML63 AMG it genuinely is press and play. The sophisticated all-wheel drive system will achieve traction in inclement road conditions and the AMG Speedshift & G-Tronic seven-speed automatic gearbox will just slur seamlessly through the gears with no apparent let up in that tidal wave of power. If you're feeling playful, it's possible to zip up and down the box using wheel-mounted shift buttons, but the system's software is so smart, you'll probably be tempted to slot it into either Comfort or Sport mode and let it do the thinking. The old ML55 AMG was a piece of work but the 63 generates 46 per cent more power and 23 per cent more torque. That's serious.

It's tempting to think that a vehicle with this bulk and power would lose the plot when it was shown a corner, but drive even the humblest M-Class and you'll realise that this isn't the case. AMG, Mercedes' tuning arm, have pulled out all the stops with this model, fitting it with a sportier version of the AIRMATIC air suspension system. AMG-specific dampers and a specially configured adaptive damping system (ADS) that keeps the ML63 AMG firmly planted to the road also feature. Body roll has been reduced, while squat and dive have been markedly quelled and a suspension height control system automatically drops the car a few millimetres at high speeds for improved aerodynamic performance.

The standard fit wheels are high-sheen 19-inch AMG five-spoke alloys and the ride and handling have been optimised for the 295/45 R19 tyres these wheels wear. That said, it's easy to see plenty of customers instead plumping for the optional 20-inch rims shod with 40 series tyres. Whichever size you choose, you've got a very big tyre footprint through which the huge AMG high-performance brakes can translate their retarding power to the tarmac.

Thankfully Mercedes have resisted the temptation to bling the ML63 AMG to kingdom come. The styling changes over the ML500 are actually rather subtle, the biggest giveaway probably being the rear apron and exhausts. The wings are slightly flared as well and there's an AMG radiator grille. Stainless steel running boards ruin any vestigial pretence of off-road ability and dark tinted rear lights are also fitted. The interior features AMG sports seats trimmed in Nappa leather and Alcantara. There are also AMG-specific door sills, steering wheel and instrument cluster. Stainless steel sports pedals with rubber grips and a 200mph calibrated speedometer will have school kids drooling.

It would be easy to get all Guardianista and give the Mercedes ML63 AMG a pasting for its sheer profligacy and, some might say, pointlessness. If you're not a target customer, that's a relatively simple task. If you were in the enviable position of being able to run an ML63 AMG without it significantly denting your bottom line, it would take a lot of restraint not to indulge. Excuse me while I check my email. Some chap in Lagos has just shown me a way to make a potful.