From here on out, anything with two doors in the BMW lineup will have an even-numbered designation, meaning that the 3 Series Coupe will now become the 4 Series. The big exception to this rule, of course, is BMW's new-found passion for the four-door coupe. The 6 Series Gran Coupe made its debut this year, but next year a smaller version of this design is on its way to the U.S. courtesy of the all-new 4 Series Gran Coupe.

Although this prototype looks very similar to the upcoming 3 Series GT hatchback, the sleeker roofline and lower and longer decklid are clues to the fact that this is the 4GC, but it still keeps the long hood that has become a key element of the 2012 3 Series sedan (F30). Our spy photographers also said that this 4 Series Gran Coupe appeared to be a little bit longer than a standard F30 sedan.

No official word on powertrains for the 4 Series Gran Coupe, but it should carry over the same engines as the current 3 Series sedan. That means we can expect 428i Gran Coupe and 435i Gran Coupe names with BMW's xDrive all-wheel-drive system likely folding into the mix, as well.

In addition to this model, we've already spotted the BMW 4 Series a few times this year in coupe form as well as convertible both with the retractable hard top up and down.