Something strange happened two years ago at Switzerland's annual caucus of ultra-luxury car makers. Rolls-Royce, a brand dedicated to the driven, not the driver, unveiled a vehicle that had just two doors, an engine the size of a small Jacuzzi, and a transmission that pinged satellites in order to adjust to the road ahead. The Wraith, as it was called, had no space for ajar of Grey Poupon.

“We’re evolving,” says Eric Shepherd, president of Rolls- Royce North America, about the shift into a sportier model. “Take a 22-year-old guy who just sold his app company for $22 million. When he gets behind the wheel of a Wraith, he’s hooked.”

The first Bentley Mulsanne sold at auction in 2009 for $500,000. “The number of people being able to enjoy a luxury product is not a limiting factor,” says Bentley's director of marketing and product strategy.

Things have grown ever more strange for the one percent on four wheels. The fancy cars seem to be multiplying and taking unexpected shapes. Bentley moved to build an sport utility vehicle in 2013, a decision matched by Rolls last week. Ferrari has brought out a 963-horsepower supercar with an electric motor, which has since been joined by an $840,000 Porsche with two electric motors. Orders and eager deposits started have been pouring in.

Thanks to a bullish economy and a burgeoning crop of multi-millionaires all over the world, the handful of carmakers catering to the very richest have finally started to figure out that they have been drastically underestimating demand for six- and seven-figure vehicles. That realization has fueled a new generation of interesting machines whose eye-popping price tags have widened the ultra-premium market. At the moment, unlike in decades past, the fastest-selling products in the auto business are also the ones that cost the most.

In the past five years, global registrations of the seven largest ultra-premium car brands–a group that also includes Aston Martin and Lamborghini–have surged by 154 percent, far outpacing the 36 percent gain in overall car sales worldwide. Much of the growth has come from Maserati and Porsche, two companies that sell many of their vehicles for less than $100,000. Even excluding those brands, however, the swanky car segment has swelled by 62 percent since 2009.

Rolls-Royce registrations have risen almost five-fold. Almost 10,000 new Bentleys cruised onto the streets last year, a 122 percent increase over 2009, while Lamborghini rode a 50 percent increase to pass the 2,000 vehicle mark.

For a growing class of customers, even the highest priced products don't have enough curb appeal if they come from a high- volume carmaker. "BMW has a broad range, but some people will find it's not differentiated enough," says Xavier Mosquet, head of the auto practice at Boston Consulting Group. Rolls-Royce, a brand owned by BMW, might command a fraction of the business of its corporate parent—but Rolls is also there to welcome those who feel compelled to trade up from a mere 7-series sedan. Meanwhile, much of the spoils from the boom in ultra-luxury sales are being split between Fiat Chrysler, which owns Ferrari and Maserati, and Volkswagen, which has Bentley, Lamborghini, and Porsche in its high-end garage. 

The boom in business, for the most part, comes from a simple supply-demand relationship: Growing ranks of wealthy consumers want more opulent toys. At the end of last year, about 211,000 people had a net worth of at least $30 million—a 13 percent increase from 2011, according to UBS and the research firm Wealth-X. For a person worth $30 million, purchasing a car for a mere $100,000 isn’t a weighty decision. It’s akin to the median U.S. consumer with net worth of $45,000 swinging by the used car lot and dropping $1,350 on a well-worn Pontiac Aztek.

If a car executive widens the target market to those worth at least $10 million, the population of possible customers hits almost 700,000. “The number of people being able to enjoy a luxury product is not a limiting factor,” says Christophe Georges, director of marketing and product strategy at Bentley. “The market has the potential to go far beyond where it is today.”

As the pie has grown, carmakers have done a better job of tracking down the newly ultra-affluent and convincing them to splurge on a space-age wedge of carbon fiber or a wood-paneled den on wheels. "It's been a pretty nice growth story," says BCG's Mosquet. "A lot of the growth has been triggered by new geographies."

China, in particular, has been ripe for rich rides. The country's share of the ultra-luxury car pie has swelled from 12 percent to 27 percent over the past five years, according to IHS. For Maserati and Rolls-Royce, China is now a larger market than all of Europe. Growth is also spreading across the rest of Asia and through the Middle East and Africa, regions where more people are hurdling over the $30 million mark faster than anywhere else, according to UBS and Wealth-X.

Not surprisingly, blue chip dealerships are following the money. Last year, for example, Rolls-Royce opened showrooms in both Cambodia and Vietnam. “Even if it’s only 20 or 30 millionaires in the whole country, these guys are thinking, ‘Maybe I should start buying the things to flaunt my wealth a little bit,’” says Ian Fletcher, an analyst at IHS Automotive.

Car companies are also doing a better job of price segmentation, the practice of separating customers by willingness to pay. For thousands of elite consumers, there's not much difference between spending $300,000 on a car and $1.2 million on a rarified version of the same kind of car. This explains the recent rash of ultra-expensive sports cars produced in small batches. Ferrari only made 499 of the LaFerrari, the surprise hybrid sports car rolled out at the 2013 gathering in Geneva. Each one had a price tag above $1 million. Porsche, meanwhile, made only 918 of its Model 918, a car that started at $840,000. Lamborghini bested them both, making just three of its 12-cylinder Veneno model and selling them for $3.9 million each.

The supercars that don’t aim for the top end of the speedometer, meanwhile, have focused on offering custom options. Four out of five Rolls-Royces sold last year went through what the car maker calls its "bespoke process." The coaches can be had with hand-engraved picnic sets, embroidered headrests, lambs-wool floor mats, and light-up hood ornaments. Rolls-Royce craftsmen will even stitch hundreds of diamonds into the ceiling lining to resemble a night sky—not just any night, but the constellation pattern evident on a specific date.

It’s not unusual for such extras to drive the price of a Rolls above $600,000. “We fulfill our owners’ desire to spend their money creatively,” Shepherd says. “If it makes the car totally unique, it’s much more valuable to them.”

IHS expects the super-premium car market to expand by an additional 21 percent in the next two years, and blue-blood carmakers may blow past that target if their plans pan out. 

Emboldened by their progress in emerging markets, nearly every luxury brand in the business is designing an SUV, an outbreak of product pragmatism that high-end brands once believed would ruin their finely crafted reputations. The very idea of Lamborghini making a vehicle for utility, rather than speed, is as scandalous to some as La Bernardin offering a gut- busting burrito. But the top of the car market is simply bowing to demand from buyers seeking bigger, boxier rides made by the brands they already favor.

Porsche has shown how easy it can be to make a pile from SUVs. The brand's biggest offering—the Cayenne—accounts for 35 percent of the company’s U.S. sales by vehicle, and adding a sport-utility option hasn’t soured drivers on its 911 sports cars. Porsche even doubled down on SUVs last year, rolling out a smaller model dubbed the Macan.

“The ultra-premium brands know what their customers want, and they’re going to give it to them,” says IHS’s Fletcher. “There are plenty of people around the world who will buy a Range Rover and go to someone that will double the price of the vehicle just by adding new paint and other things.”

Lamborghini's SUV, the Urus, is being put through the paces before reaching showrooms; so, too, is the Maserati Levante. Rolls-Royce became the latest to join the crowd, although it deigned to use the initials "SUV" in its product announcement last week: The company prefers to call it a"high-bodied car" able to "cross any terrain."

Bentley looks poised to beat its fancy rivals to market and promises to unveil its road-ready Bentayga SUV sometime in the third quarter. Once it hits dealerships in early 2016, the company expects to sell at least 3,000 SUVs per year. If Bentley's traditional car business remains at current levels, that would represent an immediate 30 percent boost in volume.

“We basically want to create a new market segment,” Bentley's Georges says. “If other people are thinking of doing the same, it just means our idea is not so bad, huh?”