The S-Class became Mercedes-Benz' flagship line in 1972 and still is even up to the present. The 'S' signifies "Sonderklasse" or special class and is mostly a 4-door sedan line with a brief appearance of coupes from 1981 to 1997. The S-Class is currently in its 5th generation.
The Mercedes-Benz W221 is the current and 5th generation of the very luxurious S-Class. It replaced the
W220 and is more like the Daimler flagship Maybach than its predecessor. Introduced in 2005, it started with only 4 models: the S350/L and the S550/L. Most of the models came in 2006: the S300/L, S450/L, S450/L 4MATIC, S63/L AMG, S65 AMG, S600, S320/L CDI, S320/L CDI 4MATIC and S420/L CDI. The S350/L 4MATIC was added in 2007 and the S320/L CDI BlueEfficiency in 2008. In 2009, the W220 underwent a minor face-lift to accommodate new automotive features and more models.