The new Mini Convertible will go on sale in New Zealand around Christmas, wearing the Cooper badge and powered by a 85kW/115bhp engine.
The premium soft-top Cooper S and its 120kW/163bhp engine will arrive next year.
But Minis over the next couple of years are expected to be fitted with more powerfulversions of its 1.6-litre four-cylinder motor.
The South American-built engine, jointly developed by BMW and Chrysler, has been criticised for lacking refinement and low rev torque.
Reports in Britain have it that a new 1.6-litre unit - to be assembled at BMW's Hams Hall plant in the Midlands - will replace it next year.
Not only will it offer better performance and smoothness, say the reports, but also improved fuel economy.
A 96kW/130bhp engine is planned for the Cooper and a supercharged 135kW/180bhp unit for the Cooper S. There is also talk of BMW developing a 2-litre engine for the Cooper S.
The Convertible will be unveiled at the Geneva motor show next month.
The roof with its heated glass rear-window opens and shuts in about 15 seconds at the touch of a button. The folding roof collapses to the rear, the roof pillars automatically re-tract into the car and the two rear side windows move down completely.
The roof is finally folded into three layers on top of one another, resting in behind the rear seats. BMW says the way the roof packs means there is no need for a tonneau cover.
Another feature of the roof is the sliding function, which allows the roof to be open part way. This can be done up to speeds of 120 km/h.
BMW says integration of the rollbars - made of extra-stength aluminium tubing behind the rear-seat backrests - gives the interior of the Convertible virtually the same character as a roadster.
"Although the closed roof of the Convertible may appear somewhat lower and squatter, headroom remains unchanged."
The Convertible comes with four airbags, two at the front and two on the side of the front seats, and three-point safety belts on all four seats.
Ten exterior colours are available, two of which are reserved exclusively to the soft-top: hot orange and cool blue.
BMW says the body of the soft-top has been strengthened to improve torsional stiffness.
