According to French magazine L'Automobile, insiders at BMW have confirmed plans to reveal a new model based on the existing (but still to launch) i3 hatch.
The report adds that the new i car will take on a more coupe-like appearance, sticking with three doors but dropping the i3's rear seats.
If BMW is indeed planning a third i car, expect it to retain not only the i3's general architecture, but also its petrol-electric plug-in hybrid drivetrain.
In concept form, the rear-wheel-drive i3's output is listed at 125kW and 250Nm of torque, with power transferred through a single-speed transmission.
BMW promises a 0-60km/h time of 3.9 seconds and a 0-100km/h run of 7.9 seconds - quite spritely for a city car.
The carmaker says i3 owners - likely to be primarily urban dwellers - can expect to get between 130 to 160km from one charge.
Watch for more details on the i4, and the already-revealed i3 and i8, in the coming months.