► We ride in Mercedes-Maybach Pullman

► A staggering 6.5m-long leviathan, with a 1.35m door!

► Armoured version celebrates 50 years of protection

What do Elvis Presley, Pol Pot and the Pope have in common? The Mercedes-Benz Pullman. For 52 years, this six-seat state limousine has been the Ford Galaxy of the 0.001%. This year, the armoured version celebrates half a century of protecting dictators who met a grisly end anyway: Hussein, Gaddafi, Ceausescu. And now there’s a new one. This time badged the Mercedes-Maybach Pullman, it is the new patriarch of the S-class family and the new ride of choice for despots everywhere.

So far only two have been hand-made, and I’m being chauffeured around Dubai in one of them before it goes on display at the motor show here. Dubai is awash with Zondas and LaFerraris and P1s costing well in excess of the Pullman’s £350,000 base price, but our car still attracts huge attention. People seem to know that it is more than just a stretched S-class. ‘In the Gulf, around 70% of Pullman customers are royal,’ explains Markus Rubenbauer, Mercedes’ head of Pullman and armoured cars. The locals do little to disguise their confusion at finding a solid German engineer and an impoverished Irish journalist in the back seats, rather than the aquiline features of their hereditary Emir, Sheikh Mohammed. I motor the curtains closed to save disappointment.

The new Pullman was first revealed at the 2015 Geneva motor show. On the very first day of the show, while I was reporting on the unveiling of another Korean econobox, some plutocrat was on the Mercedes stand, ordering three Pullmans from Rubenbauer to ensure that he got his first. Those cars will be delivered early in 2016. Markus won’t say how many Pullmans will be built each year: just that they’re sold out until 2017 and that Mercedes ‘wants the cars in the hands of the right people’. I’m not sure that Robert Mugabe and Idi Amin constitute ‘the right people’. Mercedes made only 302 examples of the original 600 Pullman over 17 years.

Rubenbauer is predictably discreet about who the customers are, but he confirms that they include heads of state, and that most put tyrannising aside for a moment to personally choose at least the colour and trim of their new official ride. In fact, this new Pullman was designed with the input of the Security Council set. The office of German Chancellor Angela Merkel wrote to Mercedes thanking it for the loan of the last-generation Pullman for state duties (buying one would be extravagant) but asked if the door could be made even longer. Protocol demands that heads of state enter the car first; the problem was that their interpreters then had to shuffle past them like middle-seat latecomers at the movies in order to get into the rear-facing seats. You cannot show your backside to a president or a king. A more fitting solution was required.

The answer is the new Pullman’s colossal 1.35-metre-long rear door. It is almost long enough to take late diminutive Pullman fan and keen anti-imperialist Kim Jong-Il if you inserted him horizontally. It’s made possible by the fact that this is not a standard Maybach that has been cut in two and stretched. The Pullman was in the S-class product plan from the start, and its 6.5m-long body-in-white is pressed out like any of the S-class’s five other body styles. This also allows the designers to ensure the Pullman doesn’t look whale-like despite its extra 1.4 metres in length over a standard-wheelbase S-class, and its ten extra centimetres in height. The gently rising roofline is graceful, and two deep side-strakes help break up the car’s visual mass.

So you’ve overthrown the old guy, installed yourself as President for Life, pinned a row of medals to your chest and bought a Pullman. How’s the ownership experience? That door is predictably heavy, but Mercedes’ research shows that in 90% of ‘door-opening events’, someone other than the rear-seat occupants will be doing the work. Should revolutionaries shoot your footman, a motor will do the job instead.

Once through the door you sit back behind the door opening, looking out partly through the quarter light. Markus calls the rear cabin a ‘plastic-free zone’: everything, including that vast prairie of headlining is made of leather, wood or metal. Having had an accident with the maple syrup at breakfast, I washed my hands before I got in. The carpets can be soft, inch-deep lambswool rugs which engulf your shoes because the occupants will never step in dogshit or chewing gum.

There are gadgets to preserve your privacy, such as the powered curtains on all windows, and the glass divider which slides up to shut out the driver and turns opaque at the touch of a button so he can’t see you weep at the futility of it all. You can still instruct him via the intercom (you know your car is large when it requires its own internal communications system).

Otherwise the cabin is remarkably sober and gadgets are limited. The main seats recline, of course, and have pop-out calf supports. There’s a fridge and beautifully-engineered fold-out tables in the divider. There are small screens in the base of each rear-facing seat, visible when they’re folded up, and an 18.5-inch flatscreen which motors up from the driver partition. The hallmark Maybach rear-cabin dials for speed, time and temperature are mounted in the roof, as are two of the 24 Burmester speakers.

There are surprisingly few options. Rubenbauer says the Pullman has been kept deliberately simple to order because the customers are kind of busy. For £10,000 you can upgrade the already insanely good audio system to ‘high-end 3D’ status. And for another £7000, Burmester will run some speakers in on the bench, listen to how their tone changes as they’re broken in, and fit your car with the speakers that best match each other and the type of music you most like to listen to. The result is easily the best audio I have ever heard in a car, or ever will. You can also splash £18,000 on a panoramic sunroof, and the base price of the car again on armouring. Needing armour is the sign that you’ve really made it: Hugh Hefner didn’t need to armour his, but you can bet Vladimir Putin does.

I didn’t drive the Pullman. It seemed about as relevant as President Obama wondering what Air Force One is like to fly. I assume that the chauffeur gets the same tech-fest that marks all-new S-classes, but does Lord Grantham care if Mrs Patmore’s Aga has a temperature gauge? Far more important is how it feels in the back. The answer? Eerie and quite un-car-like, both in the utter sense of isolation it offers (especially with the curtains closed and the partition screen opaque – then it feels like a small private jet) and in the way it moves.

That vast wheelbase means the Pullman pitches far less over speed humps, and you can see the front end turning long before you start to pivot at the back. Motoring journalists like to talk about the ‘distant thrum’ of a refined, multi-cylindric engine, but in this case the 523bhp, twin-turbo 6.0-litre V12 really is a long way away. Pleasingly, it’s not Tesla-silent, but any vibration dissipates long before it reaches your royal backside.

But the Pullman’s greatest and defining features are those rear-facing ‘interpreter’s’ seats. That’s how Mercedes describes them, but you can put anyone you like in there: your bodyguards, two of your concubines, your nuclear-code-carrier, your psychotic brother-in-law whom you made chief of your secret police. I put Markus in there and found that we both had plenty of legroom, although the guy in the dicky-seat would be well-advised to keep his feet tucked in. I tried them too, just to experience the oddness of travelling backwards in a normal-height car. They’re a little firm. Their occupants would be wise not to complain.

It saves getting the Gulfstream out…

Khalid al Marzooqi is one of Dubai’s top Mercedes salesmen. I took him for a ride in the new Pullman to get his views on what his fellow Emiratis would make of it. Despite Dubai’s huge wealth, he expects only three or four to make their way here, mainly for the ruling al-Maktoum family. His ‘ordinary’ customers buy more G-wagons than any other model, followed by the S-class and C-class.

Most customers just want a car with every option, even if they’ll never use them, and they want their cars immediately – few want to order something bespoke and have to wait for it. Limousines are used for short chauffeur-driven trips between home, office and airport, but also for longer trips along the Arabian Gulf coast between the Emirates if it’s quicker than firing up the chopper or the jet.

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