What is it? Although officially just a concept, this is the car that apart from the door handles, side mirrors and rear apron will replace the 3 Series coupe.
Much as the 6 Series became the coupe/convertible of the 5 Series, from now on the 4 Series will be the coupe and convertible of the 3 Series. Although components and powertrains are shared with the 3 Series sedan, the coupe is lower and has a wider track, and the styling is elegant yet more muscular.
It's reasonable to assume that the version hierarchy will follow that of the sedan with the 428i being powered by the 2.0-liter turbo four-cylinder, the 435i having the 300-hp turbo straight six and eventually there'll be a high performance top-of-the-range M4.
The 4 Series coupe will also offer all-wheel-drive, as does the outgoing generation, and very possibly, BMW hints, an AWD convertible. That would make sense, as it would be a competitor to the Audi A5 AWD convertible, which currently enjoys a monopoly.
What's still unclear is whether the convertible will continue with a retractable hardtop or move to a lighter, faster-folding soft top.
When will it be available? Fall 2013.