BMW has already released the next generation 3 Series, which goes by the internal code designation G20. In typical BMW fashion, the 3 Series Coupe and Convertible, which were renamed as the 4 Series in the previous generation, will be revealed at a later time. We don't know when exactly but we do have a few spy shots showing the convertible version with a new fabric roof to replace the metal hardtop.

The 4 Series should be mechanically similar to the 3 Series in terms of engines and transmissions, meaning either a 2.0-liter four-cylinder turbo with 255 horsepower or a more potent 3.0-liter inline-six with 382 hp will sit under the hood. Although the engines should be shared with the 3 Series, we learned at the recent 3 Series press drive (full review coming later this week) that the 4 Series will look significantly different than its four-door counterpart.

We chatted with BMW 3 interior design chief Brunco Amatino who explained that "The new 4 Series will look nothing like 3 Series. Not a single millimeter inside, too. Every family (of BMW models) has its own unique design. Everything the customer sees and touches should be different." This statement does not offer specific styling details, but it does inform us we should expect something quite different for the new 4 Series.

Considering the new 3 Series is a significant departure from the outgoing model, the new 4 Series should be quite different as well. Amatino also confirmed the 4 Series lineup will return in full for the next generation. This means the coupe, convertible, and Gran Coupe body styles should all make a return.

BMW has already announced the 3 Series GT will not continue into the next generation and may essentially merge with the 4 Series Gran Coupe.

"We want to take the largest (design) step inside and out you can imagine without scaring the customer," Amatino added. BMW has yet to provide an official launch date for its second generation 4 Series lineup, but the outgoing model premiered around a year after the sedan, to give you an indication.