2009 BMW 3 Series

For its third year on the market, BMW is giving its bread-and-butter model a healthy list of small improvements to make it even more desirable. Among the changes are (slightly) revised styling, an upgraded interior, simpler iDrive interface, in-car Internet access, a new audio system, and an optional dual-clutch transmission. The automaker's sublime 3.0-liter inline-six, available in both naturally aspirated and twin-turbo form, remains the same, but for the first time BMW is also giving Americans the option of a diesel powertrain -- and it could turn out to be the best of the bunch.