Although we make every effort to cover our own travel costs, in this case BMW flew me to Palm Springs, California, and provided two nights in a hotel in Indian Wells.

Now that SUVs have overtaken sedans as a percentage of all new car sales in the United States, it's no surprise that ultra-luxury carmakers have jumped on the bandwagon. People accustomed to spending something well north of $200,000 on cars now have options like the Lamborghini Urus, Bentley Bentayga, and Range Rover SV Coupe. So when presented with an unexpected opportunity to take a Rolls-Royce Cullinan for a spin down desert highways and an off-road course, I leapt at the chance. Especially the off-road bits—one of the most frequent comments in luxury SUV reviews is "no one is ever going to take that off-road."

That may very well be true for the Cullinan, which debuted in late 2018. But if the road to one of your winter chalets—say, the one in the Sierra Nevadas—is blocked by a mudslide or avalanche, you'll still have a shot of making it home in time for cocktails if you're behind the wheel (or in the backseat) of this elegant beast. Before we get into the ups and downs of driving a Cullinan, let's look at the numbers.

The obvious figure to start with is the sticker price. MSRP for a Cullinan is $325,000. To that, add adaptive cruise control, parking assistant, rear theater configuration (more on that below), and a bunch of interior finishing touches (you simply must opt for the Open Pore Royal Teak), and the sticker price for this luxury on wheels comes to $395,025. [That might make it the most expensive car we've ever tested—Ed.]

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

In terms of the mechanical bits, the Cullinan sports a 6.75-liter twin-turbo V12 engine capable of churning out 571hp (421kW) at 5,000rpm and 627lb-ft (850Nm) of torque at 1,600rpm. This helps propel this 5,864lb (2,660kg) behemoth—crafted of only the finest steel and aluminum—down the highway at speeds of up to 155mph (250km/h). To give the Cullinan the lush, quiet ride that one expects from a Rolls-Royce, it has a double-wishbone suspension and all-wheel drive.

Although it's an unfamiliar form factor, there's not a scintilla of doubt that you're looking at a Rolls-Royce. The Spirit of Ecstasy takes her place of honor at the front of the hood above the front grille. The Cullinan has the familiar square, even boxy, lines of a Rolls. And, of course, there are the suicide doors and the weighted center caps that keep the Rolls logo in the center of the wheels always upright.

Behind the wheel and in the back seat

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

My encounter with the Cullinan came at the BMW Test Fest in Thermal, California. Since 1998, Rolls-Royce Motor Cars has been part of BMW, so there was a pair of Cullinans available for brief excursions down to the shores of the Salton Sea or up into the San Bernardino Mountains. Just around lunchtime, one of the Cullinans became available. Another writer was looking to get some time in the car, so we did rock-paper-scissors to see who would sit in the back seat. He won, so I took the wheel for the 18.5 miles down to the Mecca Beach Campground on the shores of the Salton Sea.

As I climbed into the driver's seat, I scanned my surroundings, which were trimmed in stainless steel, santos palisander (similar to Brazilian rosewood), and leather. My sightlines were good and my seat comfortable. As I put the car in reverse, the same backup camera and 360° top-down view I'd seen in a BMW appeared on the HD display. (Rolls-Royce uses a skinned version of iDrive for its infotainment system.)

Our route took us down Highway 111, a two-lane highway that was largely free of traffic once we made it out of Thermal. All that was in front of us was the Spirit of Ecstasy on the hood and an open road.

You would expect a Rolls-Royce to be quiet—and you would be correct. Even at higher speeds, there was a degree of detachment from the surroundings that is rare. You would never know how hard the V12 engine might be working, as the Cullinan was a perfect Edwardian gentleman with impeccable manners and a sort of effortless but powerful grace. Gear shifts with the eight-speed automatic transmission are buttery smooth, and the car was more nimble (in the large SUV sense) with a turning circle of 43.4ft (13.23m). The only real "whoa" instance came when I pressed the brakes hard. When you're dealing with nearly three tons of car, the brakes can be divey.

Once we arrived on the shores of the Salton Sea, it was time to take some pictures and then trade places for the return trip. Most of the time, I prefer to be behind the wheel; in the case of the Cullinan, I was more than happy to be in the backseat.

There's scads of room behind the driver. After all, the Cullinan is a full-size SUV at 210.3in (5,341mm) long, yet it only seats four and has just 21 cubic feet (600L) of cargo space. The seats are more than comfortable, and passengers can while away the miles by playing with the tablet that folds down from the front seats. You can play media, check out a map of where you're going, and even control the radio.

It goes off-road, too

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Eric Bangeman

Later in the day, I was a passenger in the Cullinan as Gerry Spahn, Rolls-Royce North American director of corporate communications, put it through an off-road course that was there to show off the capabilities of the BMW X5 and X7 (more on those cars at a later date). The first time over the course, Spahn neglected to hit the Everywhere button on the center console to raise the Cullinan to its maximum height, so there was a bit of scraping against the underbody that made me thankful I wasn't the one driving this $400,000-ish car. That was remedied for the second circuit.

On both laps around the course, the Cullinan's electronically controlled shock absorbers did their best to insulate us from the bumps, berms, hills, and ditches of the course. The air-compression system of the Cullinan helped, as it strives to keep each wheel in firm contact with the terrain while sending the appropriate amount of power to each wheel. Front camera view on the HD display made it possible to see when we would hit the summit of the steep hill on the course, and the Cullinan's 21.2 inches of clearance made crossing a massive puddle a breeze.

The ride wasn't smooth, but it was impressive nonetheless: a posh SUV normally associated with country clubs and polo grounds getting down and dirty on a course designed to tax any car's off-road capabilities.

Chances are none of us is going to be shopping for ultra-lush, ultra-expensive SUVs any time soon. And those who are probably aren't going to be taking their purchases over rutted dirt tracks. But if you're in that tiny category—maybe the one percent of the one percent—that wants the combination of an impeccable luxury ride with solid off-road credentials, the Rolls-Royce Cullinan is there for you.