You will not hear him talking about them, however. Ostentation simply is not his style, which makes him exactly the sort of customer AMG would choose too.

AMG was founded in 1967 as a builder of racing engines. It chose to base its efforts on Mercedes-Benz, which had not officially raced since the 1955 Le Mans disaster and which, in the late 1960s, was a dowdy brand.

This proved no handicap to AMG. Its first race success was a class victory and second outright in the 1971 Spa 24-Hours with a 300SEL 6.9 limousine. People began to associate AMG with the Mercedes-Benz brand. The relationship became more legitimate when Mercedes-Benz, on deciding to return to motor sport in 1988, contracted AMG to run its German Touring Car Championship (DTM) team.

A technical agreement to produce road cars followed in 1993. The first fruit of the union was the C36, followed by the E50.

Doohan's affair with the brand began then, and he was a walk-up customer for one of each. In 1999, the AMG brand was taken in-house, although AMG cars and parts are still largely produced at AMG's own annexe in Affalterbach, Germany.

If AMG's cars are not for everyone, it has to be said that the SL65 - one of the brand's flagship models - is for fewer still.

Even after you get past the $3,298,000 price tag, the SL65 plays a numbers game which not every well-heeled buyer is equipped to keep up with.

Before the launch of the SL65's V12 engine, shared with the CL65 coupe and S65 limousine, the supercharged V8 from the SL55 was the most powerful engine in the Mercedes-Benz range by a comfortable margin of 33 per cent. The 5.5 litre V8 is incredibly forceful, exhilarating and supercar-swift, going from 0-100km/h in 4.8 seconds. You would think that was enough stomp, acceleration and cylinders for anyone.

The V12 SL65, however, has two turbochargers, 603bhp and a jaw-dropping 1,000Nm of torque.

The engine cannot help but dominate the SL65. As with all AMG engines, it is assembled from start to finish by one engineer who, after filling it with oil, affixes his nameplate to the carbon-fibre engine cover.

The twin-turbocharged, 36-valve V12 starts out like that of Mercedes' regular S/SL/CL600 production models, but has its capacity stretched to 5,980cc (from the standard 5,513cc), primarily through a 6mm increase in stroke. On top of this come larger turbochargers with a higher boost cap of 1.5 bar, pushing air through an air-to-water intercooler 70 per cent larger than that on the standard 600.

One of the big differences between AMG and any of a dozen aftermarket tuners is that the Mercedes-Benz factory has to warrant AMG's work. So, it is fair to say that probably the effort that goes into AMG's under-bonnet wand-waving is aimed at matching drop-dead horsepower with durability.

In the SL65, this equates to a stronger crankshaft, forged pistons (with individual oil cooling jets), stronger bearings and a higher-volume oil system.

As far as the driver is concerned, however, there is no need to think about the strengthened clutch plate, and beefed-up components needed to cope with truck-sized torque and a kerb weight not far shy of two tonnes.

AMG recalibrates the SL's already impressive Active Body Control, adding its own, stiffer struts. The SL's software, including ABS, is all redone accordingly, given the various push-pull effects of the monster engine, 19-inch Bridgestone Potenzas (255/35 front, 235/30 rear) and 390mm-diameter front discs with eight-piston calipers.

The driver needs only smirk at the 360km/h speedometer (though the car is limited to 250), and practice your ballet-steps ... because, merely tweaking the throttle from standstill uncorks a whooshing wall of torque.

Consider that by around 1,200rpm the V12 is already developing more torque than the supercharged V8 makes at its peak. Without the most delicate of throttle inputs, a simple three-point turn in a city environment threatens to induce whiplash.

Get the car out on the open road, however, and there are few better qualified to suck up and spit out continents.

Imagine a huge, huffing, six-litre engine. Imagine a smooth, syrupy, high-revving V12 engine. Imagine an urgent, excitable, twin-turbocharged engine. Then imagine all three in one.

As with the standard SL, the 65's chassis has an agility that belies its kerb weight. The brakes are mighty, helping to swat speed from the instrument needle, which is just as well because the SL65 builds momentum with deceptive ease. The one sour note in the SL65's repertoire is the front-end's behaviour in hard cornering. While it tracks resolutely and the steering weight provides adequate feedback under normal conditions, its inevitable surrender to understeer is accompanied by a shuddering, chopping feedback through the wheel.

While this is not hugely unsettling to the driver, and even less so to the directional stability of the chassis, it is made more remarkable by the fact that the V8-engine SL55 does not do it at all.

Indeed, the lighter-engine version is actually better behaved and easier to drive for all but a handful of transcontinental conditions.

SPECIFICATIONS

Engine: twin-turbocharged six-litre SOHC 36-valve V12

Power: 603bhp @ 5,500rpm

Torque: 1,000Nm @ 2,000-4,000rpm

Transmission: five-speed electronic automatic with overdrive

Acceleration: 0-100km/h in 4.2 seconds

Top speed: 250km/h (speed limited)