The 2009 Mercedes-Benz M-Class SUV is a far cry from the original model. Whereas the first M-Class featured body-on-frame construction, the newest ML employs a unit-body design. This creates a stiffer chassis, which helps eliminate rattles and vibration as well as quiets the interior. The design also allows for a more sophisticated suspension, yielding better handling and a more civilized ride. Although it can seat five, the ML is most comfortable with four passengers. It offers a modest cargo bay of 29.4 cubic feet, which is more space than an Infiniti FX35, but less than offered by the Acura MDX. The M-Class' BlueTEC diesel engine option is unique in this class, and Mercedes-Benz promises the engine will meet all 50 state's stringent emissions standards.