BMW's flagship M SUV is a purpose-built model that will blow you away with its enormity, huge performance, and shockingly nimble handling.

If we lived in a world where SUVs only existed as specialty vehicles, then the impending arrival of a BMW M model would be even more eagerly anticipated.

And the questions swirling in our minds would be: How low and swoopy will it be? Is it a sedan or coupe? Will it have a high-revving straight-six or V8 engine? Can it lap the Nurburgring quicker than both its predecessor and rivals from Audi and Mercedes-Benz?

But when the new M model is the ginormous XM and costs over $1m, you'll be dumbfounded. If you're a dyed in the wool M fan, you might be clutching your face in despair. But don't reach for the pitchforks and torches just yet, because if you give the XM a chance, you'll be even more gobsmacked when you discover what it can deliver.

So very special

The XM is the M division's flagship SUV, but what makes it stand out is that it is a purpose-built model. Unlike other M models like the M3 and M4 that are based on the regular-production 3 Series and 4 Series, the XM is not based on any existing model. The last purpose-built M model was the M1 in 1978.

Does it look special, though? The styling is polarising, to say the least. Designers have given the car octagonal kidney grilles that light up when you approach and are illuminated at night. Cool.

But gaze at the XM from afar and you'll inevitably conclude that it has a cyborg-like face. If you're into Star Wars, you can imagine Darth Vader, or some other Sith Lord, choosing the XM as their mode of transport.

After all, the XM's footprint is also what adds to its imperious presence. The SUV measures 5,110mm long from tip-to-tip, stretches 2,005mm wide from side-to-side (making it the widest M model), and stands 1,755mm tall. As expected, the wheelbase is over three metres long, or 3,105mm to be exact.

Other standout elements include 23-inch wheels, which could even grow to 24 inches when the XM is facelifted. Along the flanks, you'll find gold accent bands surrounding the windows, which also put a new spin on the brand's trademark Hofmeister Kink.

Further emphasising the XM's bold character are the big 'BMW' markings on the wheels, and the two laser-etched badges on the rear windscreen, which hark back to the twin BMW badges on the rear of the M1.

Speaking of which, the XM's rear end is probably the coolest-looking part of the car. Here, you'll find sleek rather than oversized taillights, and two pairs of vertically stacked exhausts. Unseen, however, are the large cooling fins beneath the car that channel air to cool the tailpipes.

Colourful nights

An M model should be filled with plenty of sporty touches, from bucket seats to carbon fibre. However, the XM's interior reflects its status as the flagship M SUV model, so luxuriousness takes a front seat instead.

The driver and his passengers are cocooned in comfort, with cushy seats and leather-trimmed door panels that wouldn't look out of place in a 7 Series. Standard hi-fi is the Bowers & Wilkins Diamond Surround Sound System, with 20 speakers and a 1,500-watt amplifier.

I'm no audiophile, but even I would say it's fantastic, for you can crank up the volume without distortion setting in. You'll want to bop along to Motown tunes. Songs from Tsai Chin and Teresa Teng sound emotive, too.

Of course, there's plenty of carbon fibre as well - the Curved Display and gearshift lever are surrounded by it. There are also alloy pedals with rubber inserts, and a meaty steering wheel with the M1 and M2 buttons, plus a pair of carbon fibre paddle shifters.

Like its other M siblings, the M1 and M2 buttons enable drivers to save their preferred drivetrain settings and recall them at a moment's notice. M1 could be the designated 'Beast' mode, while M2 could be the 'Rain' option with gentler settings.

If it's something soft you seek, then it's the rear bench you want. The backseat feels even cushier than the front, and you get a better view of the sculptural headliner. Surrounded by 100 LED units, this headliner gives the cabin a futuristic feel. The downside is that it doesn't retract because there's no panoramic sunroof to reveal.

Rocking your world

Here's where it really gets interesting: The XM isn't a conventionally powered M model, but it's not an EV (electric vehicle) either. Motivating it is a plug-in hybrid powertrain consisting of a bi-turbo 4.4-litre V8 (the S68 unit) and an electric motor that's powered by a 25.7kWh battery.

Combined, the V8 and electric motor kick out 644bhp and 800Nm of torque, figures that are sent to all four wheels via an eight-speed automatic gearbox. According to BMW, the ZF-sourced transmission is specifically developed for this model, and it's so new that little info about it exists online.

Using launch control, the XM and its M xDrive will slingshot from rest to 100km/h in 4.3 seconds. But before you scoff and say 'pffft', let's give it context: The XM weighs an astonishing 2,785kg. Imagine how much quicker it would go if it was a tonne lighter.

Dial up the engine and drivetrain settings and you'll also be speechless at how light the XM feels. Off the line, it's effortless. Put your foot down, however, and you're greeted by a torrent of endless power with a soulful soundtrack. The V8 only starts to plateau past 6,000rpm, so just below that is where you want to keep the tacho needle.

All petrolheads love V8 engines, and the S68 is lovely. It burbles at low speeds, but it builds up a lovely crescendo as you press forth. Oh, don't forget to dial up the Drivelogic settings. See that little rocker switch on the gearshift lever? Press it till you see three bars, which tells the gearbox to shift as fast as possible.

In manual override mode, which is how the XM should be driven, the V8 is at its most emotive, and lets the driver make those addictive downshift blipping noises when you slow down.

Now, as a plug-in hybrid, the XM offers an electric driving mode. In this setting with a fully charged battery, the XM can cover up to 88km and has a top speed of 140km/h. But putting your foot down and using the manual override function will activate the V8.

Zero emissions motoring is a nice feature to have, but I argue that the XM prefers a good workout, which means hard acceleration and equally hard stops. Speaking of which, only when you brake do you feel the car's weight. Despite the capable stoppers, one needs to leave respectable stopping distances, especially with a full complement of passengers on board.

But when you're alone, throw the XM around corners and you'll be wowed. Active Roll Stabilisation, which uses a 48-volt motor between each half of the front and rear anti-roll bars, ensures that the nose remains flat during cornering and minimises leaning as well.

Integral Active Steering (rear-wheel steering) further increases the SUV's agility. The XM is the first M model to be equipped with such a system, which makes it more manoeuvrable than expected.

Indeed, a car with these dimensions has no business emerging from bends with its feathers unruffled, and yet it does. No matter how tight the corner, the XM seems to just find a way around it. And if it can't 'flow' through it nicely, it'll dominate it.

Even tight carparks, such as the eerie Pearl's Centre carpark along Eu Tong Sen Street, did not seem to faze this SUV. That said, no matter what car you drive, take care when leaving, because the exit lanes narrow considerably.

Then leaving you plenty to ponder

The XM has two bugbears to be aware of. One, the ride might be too firm for some, for 23-inch wheels and steel springs do not bode well for ride comfort.

Two, this enormous SUV has equally stupendous blind spots. Even with the blind spot monitor, turning your head 90 degrees to check before switching lanes is a must. Those thick C-pillars can keep a lot of other road users out of sight (and out of mind).

Should you buy an XM? It's a tough call. The XM polarises opinions and gives rise to questions such as 'Why is a flagship M model an SUV?' and 'Why a plug-in hybrid? Can't it just have a V8?' Or 'Why couldn't BMW just have made it an EV?'

There'll never be a right answer. For all the pleasure that the XM offers with its outrageous performance and luxurious cabin, its dimensions and stiff ride are pain points to live with. But if you like it for what it is, call it the S&M X&M and give your bank account a million-dollar spanking.

ALSO READ: BMW XM launched in Singapore

This article was first published in sgCarMart.