Don't get confused by yet another numerical addition to the BMW
lineup. The German automaker announced months ago that the upcoming two-door version of its 3 Series sedan will be rechristened the 4 Series. The apparent logic behind this change is simply to differentiate the coupe from its sedan counterpart just like Audi
has done with its A4/A5. Everybody getting this? Good, because Bimmerpost is reporting that the 4 Series concept will debut this January at the Detroit Auto Show.