The 2008 Mercedes-Benz CLS-Class is a four-door, four-passenger luxury coupe. It comes in two trims: CLS 550 and CLS 63 AMG. The CLS-Class coupe, a spin-off from the legendary E-Class, joined the Mercedes-Benz lineup as an all-new model in 2006. For 2008, the CLS-Class retains most of the characteristics of the 2006 model, with only some minor changes. As in previous years, the 2008 version is available as the CLS 550, a four-door coupe, and continues to be available as the additional CLS 63 AMG offering a breathtaking 507 horsepower. New wheel designs have been introduced and satellite radio has joined the list of standard equipment.

The Mercedes-Benz CLS 550 four-door coupe is equipped with a standard 5.5-liter, V-8, 382-horsepower engine; while the CLS 63 AMG four-door coupe has a standard 6.2-liter V-8 producing 507 horsepower. The fuel economy suffers with the bigger engine: 12 mpg in the city and 18 mpg on the highway, compared to 14/21 mpg (city/ highway) for the CLS 550. A seven-speed automatic transmission with overdrive is standard on both trims.

The Mercedes-Benz CLS is longer, lower and wider than the E-Class sedan, yet the back seat offers 7.5 inches less legroom. This, combined with the sharp sloping roof, makes the car's rear area uncomfortable for tall adults and difficult to access. The trunk has a spacious 15.8 cubic feet of storage space, similar to the cargo space in the E-Class. Interior features common to both CLS 550 and CLS 63 AMG include satellite radio and a premium Harmon/Kardon audio system with a six-disc CD changer; heated and ventilated multicolor seats; and adaptive cruise control. For 2008, all audio systems are provided with an Apple iPod or MP3 player-compatible interface. Standard on the exterior are 18-inch, seven-spoke wheels, adaptive headlights, power locks, moonroof and a power trunk. The Comand system (cockpit management and data), typical in all Mercedes vehicles, tends to be unresponsive even after a person has spent some time to get used to it.

Standard across the two models is Mercedes' patented pre-safe collision preparation system, which was initially offered only on the S-Class. Other standard safety features include side-impact air bags, side curtain air bags and active front head restraints. Optional features include an airmatic suspension, sensotronic brake control, traction control, electronic stability program and automatic slip program.