As we cram more technology into our homes, cars and palms, the ergonomics of using said advancements should be getting better. Mercedes has a few elegant systems in cars like the S-Class and new C-Class that allow the driver to play with all the onboard technology with little headache. Not so in the M-Class. The LCD screen in the easy-to-reach center dash is perfect for a touch-screen interface ... except it doesn't have one.

Instead, you have to use buttons lining both sides of the screen that correspond to functions displayed on the screen. Those functions change with every screen as you move through radio, navigation and onboard computer settings. There's also a small joystick on the far side of the dash that can move the cursor around the screen, but it's difficult to use. I found myself looking for ways to work around the system most of the time, and after a few attempts at inputting directions I simply gave up. True, we should all spend time reading the owner's manual, and owners who live with the car will eventually learn the system, but a vast majority of the cars I test are intuitive enough to use without referencing the large book stashed in the glove compartment. Strangely enough, with the optional iPod connector installed in the glove box, the owner's manual no longer fit there anyway.

The stereo system was just adequate; it didn't hold a candle to the optional systems in the C-Class and S-Class.