A line of ultra performance cars from BMW continues with the M5 and M3 coupe and convertible. Nomenclature for the series uses the alphabetical designation of M, as in muscle. The number 5 signifies BMW's mid-size 5-Series car based on the 540i sedan, and a 3 represents a 3-Series coupe and convertible out of the 330Ci. M5 stocks a 5.0-liter V8 netting 400 hp as teamed with a six-speed manual stick. M3 coupe and M3 convertible pull from a 3.2-liter in-line-six that knocks down 330 hp. The 2003 M5 adds HPS air bags over rear doors and modifies the navigation system with DVD-based data. M3 coupe and convertible show a rain sensor among standard items with automatic headlight controls and aluminum trim as a stand-alone option.