Yeah, it's basically a new 3-Series convertible.
Adding to the woes of those annoyed by the nomenclature of the BMW 4-Series, there is now a convertible version, and it’s quite a nice looking car. The model sports a folding metal roof, allowing for a much more coupe-like experience when the top is up. The model is essentially an evolution of the outgoing 3-Series convertible, which has the same roof arrangement. But the new model offers a bit more luggage space, even with the top down, and a more aerodynamic shape as well.