Most car companies like to brag about their younger buyers but Range Rover has at least one veteran owner of whom it is immensely proud. When the Queen celebrated her 90th birthday in Windsor recently, her regal wave came from the back of a Range Rover.

Not just any old Range Rover, of course. Royal viewing platforms are not a listed option. This Rangie was fitted out by the British brand’s Special Vehicle Operations, a new unit charged with extending the luxury, capability and performance of regular Jaguar Land Rover products.

For Land Rover, the first example of SVO’s work arrived last year in a go-fast version of the junior Rangie, the Sport. With an SVR badge (the “R” means racy, I suppose), this big SUV takes the fight up to the storming panzerwagens produced by German tuning houses such as BMW’s M division. When it comes to offroading, SVO has the task of making vehicles that can already go anywhere go a bit further. Models given this treatment (there are none yet) will wear an SVX badge. As it diversifies into more urban high-riders, Land Rover knows it has to flex its core competence or risk accusations it’s gone soft.

There’s also vital territory in the elite space above the top-tier Range Rover, which Bentley, Rolls-Royce and others are queuing up to explore. Range Rover would be mad to let these offroad newbies have all the Middle Eastern sheiks and Russian oligarchs to themselves. So the third strand of SVO’s responsibilities involves taking a gold leaf from the Bentley Book of Heavyweight Trim and garnishing to the max. Cars given the full treatment carry an SV Autobiography plate. The first product to get the make-me-feel-rich makeover is the Range Rover SV Autobiography. It debuted in New York last year and sits right at the top of Rangie mountain with prices starting at $330,410, about $60K above the previous peak.

Almost all of the premium goes into trim. Proper luxe requires hide from top-to-toe – even the roof lining and the windscreen pillars. The pedals and switchgear are now aluminium, along with a lot of other bits that used to be plastic. Big chunks of timber bookend the dash and sweep through the centre of the cabin. You can order a cargo floor (about $5000) that looks like a boat deck and slides out for easy loading. The dogs will love it.

The tailgate is a two-piece, as is usual in a Rangie, with a hinge-down section that’s perfect for sitting on. If you wish you can add event chairs (about $11,000) – leather, of course, with aluminium foot stirrups; they fold up into their own special bag.

Naturally the champagne and flutes fit perfectly into the chiller, conveniently located between the twin rear business class recliners. Occupants can stretch out and sink their toes into deep-pile rugs, or sit up at retractable tables that power into place and feel as sturdy as workbenches. It’s as quiet inside as a country church and despite enormous 22-inch wheels, it’s a sedan-chair ride.

From the outside, an SV Autobiography distinguishes itself with smart badges that appear to have been machined from solid ingots and a range of finishes in black or chrome that pick out vents and highlight bumpers. For the first time, there’s two-tone paint if you desire.

Only the cream of the engines is offered at this level: either a smooth, powerful 4.4-litre V8 turbo-diesel or its even more potent petrol cousin, a 405kW 5.0-litre V8 boosted by supercharging. They drive through the usual Rangie running gear, which means they can go as far into the bush as anything else on the (dirt) road.

With a long-wheelbase body, which adds $12,500, a petrol SV becomes the most expensive Range Rover you can buy, with a starting price of $368,710. Tick enough options boxes – and a few Australians already have – and your SV could finish north of $400K.

The limousine allure comes across with conviction and few missteps, although the touchscreen control system, with its Gameboy quality graphics, feels well off the pace. Elsewhere in the line-up, this has already been upgraded.

The engines offer effortless forward motion but this Rangie finishes a distant second to its British and German rivals when it comes to pure pace, with the diesel taking a leisurely seven seconds to achieve 100km/h and the petrol 5.5 seconds. You don’t hustle one of these. It’s a royal yacht. You command from the bridge.

For the green wellington brigade, Range Rover has held the offroad aces for years. But it needs to defend its position and pushing upmarket involves risk. You can hike up the feel-good ingredients and jack up the price, but simply delivering on the wood-and-gadgets count doesn’t guarantee success. You need brand clout. It won’t hurt that it has the stamp of approval from Her Maj; for Range Rover, the birthday appearance could not have been more timely. When it comes to command performances, though, Bentley and Rolls have form, too.

Happily for Range Rover, demand for superlux offroaders is going gangbusters and there’s almost certainly room for all the players. In this game of thrones, everyone’s a winner.

Range Rover SV Autobiography | Engine: 4.4-litre turbocharged V8 diesel (250kW/740Nm) | Average fuel: 8.4 litres per 100km | Transmission: Eight-speed automatic, all-wheel drive | Price: from $330,410 | Score: 4 out of 5

Jaguar Land Rover Limited: Registered office: Abbey Road, Whitley, Coventry CV3 4LF. Registered in England No: 1672070

The figures provided are as a result of official manufacturer's tests in accordance with EU legislation. A vehicle's actual fuel consumption may differ from that achieved in such tests and these figures are for comparative purposes only.