The Mercedes-Benz S-Class has been the sales leader in luxury sedans for four decades. The outgoing model remained the segment leader in sales even after seven years on the market. Indeed, half of all the cars priced over $100,000 sold in the U.S. are still S-Class Benzes. That tells you something about the reputation of Mercedes-Benz's most expensive, most elaborate sedan.Now, Mercedes has introduced an all-new S-Class. The exterior design, the interior design, and the onboard controls systems are entirely new, and all of the safety systems have been upgraded and even further integrated. Only a few parts and systems carry over from the previous-generation models, such as the air suspension system, the seven-speed automatic transmission, and most of the safety systems.