The M3 coupe and M3 convertible are the top of the line 3-series. These deliver a much-higher level of performance than the other 3 Series models, starting with a 3.2-liter engine rated at 333 horsepower. These cars approach the Porsche 911 in acceleration, braking and cornering, in a more practical package that seats five. They are based on the previous-generation 3 Series.The BMW M3 is a carryover from 2005.