It's fascinating that Mercedes can charge such a premium and still have the second-best-selling car in its class. What's more, all this has happened even as the current generation hits its fourth year. The popularity is deserved: The S-Class is aging well, and it's no longer the reliability sinkhole it used to be.

Competitors are trying to reinvent the wheel, but I don't think a luxury flagship needs to be a sport sedan, too. Mercedes knew its mission, and it hit the nail on the head.