Back when the XC90 was new, folks had a common question: why must even the world's most successful and esteemed station wagon company settle and sell out to the SUV-making masses? One answer is volume: Volvo's wagons only came in sizes small or medium, which some families feel they'd physically outgrown. The other answer is, well, volume: the XC90 has outsold every Volvo since the outset, and stated mathematically, Biggest Price Tag x Highest Quantity = Who Cares What The Critics Think?Besides, whatever the XC90 might reveal about the vanity of Volvistas, it still lets some of the brand's traditional merits shine through. After all, the XC90 traces its roots to the second generation of front-wheel-drive Volvos, which began in 1999 with the top-of-the-line S80 sedan. The proliferation continued with the V70 wagon, the rugged XC70 "Cross Country" sport wagon (which once served as the surrogate SUV), the S60 sedan, and more recently, the Ford Five Hundred and Freestyle. The cycle begins anew with the upcoming S80; the XC90 should stay a familiar face for a few more years.But it's a unique face, and a changing one. This was always the only Volvo with 5 doors and 6 cylinders, and later became the chosen one to get the brand's very first V8 (hailing from Yamaha), plus a new six-speed automatic to go with it. Last year Volvo eliminated all 6-cylinder engines from the company portfolio, but this year returns with a brand new one. Guess who gets it first?