It wasn’t all that long ago that the idea of BMW building a giant, eight-passenger SUV would have seemed downright heretical. Sedans, coupes, wagons and convertibles have been Bimmer’s stock in trade most of its existence; it waited until the very end of the 20th century to jump on the sport-utility bandwagon, even though manufacturers had been using the term for the fast-growing category for more than a decade and models like the Ford Explorer, Chevy Tahoe and Jeep