Popular and profitable variants of BMW's most important car are attired in all-new, de-Bangled sheetmetal. The coupe, convertible, and M3 will help the 3-series sedan fend off challengers for the entry-luxury-segment crown. The coupe and convertible will be motivated by the same six-cylinder engines as the sedan, along with BMW's new turbocharged six, while the M3 will have a 400-hp V-8 under its hood.