The Mercedes-Benz S-Class Pullman will have three rows and cost as much as double the top-of-the-line Rolls-Royce, setting it up to become the world’s most expensive sedan when it goes on sale next year. Priced at about $1 million with armor plating, the vehicle will be reminiscent of past Mercedes models owned by the likes of designer Coco Chanel and former Philippine leader Ferdinand Marcos. The four rear seats will face each other and be separated from a front chauffeur compartment by a partition window to guarantee discretion, according to a person familiar with details of the brand’s strategy. The Pullman will cap an ongoing expansion of Mercedes’s high-margin flagship into a line of six models, double the number of variants in the past. The plan includes a sporty coupe that goes on sale this fall. By bulking up on elite vehicles, the Daimler AG (DAI) unit is challenging Bayerische Motoren Werke AG (BMW) and Volkswagen AG’s Audi to follow as the three vie for the luxury-car sales lead. With the new top-end S-Class, “they are trying to evoke the very famous old 600 Pullman that was used by people from dictators to John Lennon,” said Tim Urquhart, a London-based analyst with IHS. “They want to show that Mercedes still stands for an absolute elite, luxury and opulence. There’s symbolic value to this kind of car.” The S-Class coupe, which rivals the Bentley Continental GT, starts deliveries in September. Chief Executive Officer Dieter Zetsche is counting on the S-Class to advance his goal of overtaking BMW and Audi in profit and deliveries by the end of the decade. The executive reviewed at least a dozen versions of the design and tested the car in Germany’s Black Forest, South Africa, Sweden and the U.S. to find the right balance between comfort and handling.