What It Is: The madness of the wealthy. When everybody else is getting drunk and jumping in the pool, you might as well hand Jeeves your tweed jacket and BVDs. The Bentley Bentayga has made Rolls-Royce’s first SUV a certainty, with the company confirming that it is working on one under the code name Cullinan, dubbed, fittingly, for a famously gargantuan diamond of 3106.8 carats.Why It Matters: Millionaires, like everyone, are moving into SUVs. A Rolls-Royce 4x4 should sell strongly to this cash-rich cohort. Plus, if you go back far enough, you discover some of the earliest Rollers were used for some pretty adventurous escapades. Back in the days before roads.Platform: The Cullinan will be based on Rolls-Royce’s new aluminum-spaceframe architecture, being developed to help move the next generation of Rollers away from their engineering links with more-plebeian BMWs.Powertrain: Rolls doesn’t really “do” fewer than 12 cylinders, old boy, so it’s as certain as the English cricket team suffering a mid-order batting collapse after tea is served that the Cullinan will have a V-12, most likely a development of the Ghost’s twin-turbo 6.6-liter. A plug-in-hybrid version will also be offered.Competition: Bentley Bentayga, Lamborghini Urus, Land Rover Range Rover Supercharged, Mercedes-AMG G65, Porsche Cayenne Turbo, Bell 206 Jet Ranger.What Might Go Wrong: Tighter fuel-economy standards will make it harder to sell luxury pluto-utes, and if the global economy tanks, demand could disappear faster than a good valet.Estimated Arrival and Price: Late 2018 and at possibly as much as the $420,325 Phantom.