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.”