On this prototype, we can very well make out the shape of the upcoming two-door coupe which should be larger than the 3-series. Or we can imagine it as a smaller version of the 6-series coupe. Speculation is that the new 4-series will feature both two-door and four-door sport coupe variants (as BMW will be doing with the 6-series as well), to compete against the likes of the Audi A5 range, and that BMW may also introduce a cabriolet version too.