The four seater is due in Australia mid-next year, according to BMW Australia spokesman Toni Andreevski.
And it might be simultaneously rolled out locally with the 1 Series Coupe that was also exclusively revealed in CARSguide last month.
The latter is due for its world debut in the next fortnight.
“It depends on availability,” Andreevski says of the models, which, unlike some BMW lines available here, will both be manufactured in Germany.
“There is nothing comparable that has rear-wheel-drive and perfect balance front to back. This will be the real driver's choice.”
The 1 Series is likely to be priced between $60,000 and $80,000.
“Historically we've owned that segment and we can expect buyer interest in a BMW coupe or convertible priced there to be strong.”
A choice of five engines will be offered globally, including a diesel which is unlikely to reach Australia, at least in the near future.
Of more importance, though is the range-topping 135i. Sharing the acclaimed bi-turbo 3.0 inline six first seen in the 335i and due nest in the 1 Series Coupe, it will lead the local lineup and account for as much as 50 per cent of the model line's sales if the 3 Series equivalent is any guide.
Of the three other engines - the atmo six-cylinder 125i, the four-pot 120i and 118i - BMW Australia is likely to take the first two.
With a claimed 0-100km/h time of 5.6 seconds, the 225kW/400Nm 135i is a good half second quicker even than Porsche's superb Boxster S roadster. European Union testing posits combined cycle fuel consumption of 9.4 litres per 100km.
It has a modified M Aerodynamics Package from the M Sports Package as standard, which includes front skirt, door sills, rear skirt are identical in their details to those on the forthcoming coupe. The M theme continues beneath with sports suspension and a high performance braking system as standard.
There are two standard colours available in the soft-top range, classical black or beige. It can be optioned in an exlcusive anthracite with silver effect.
While folding hardtops are the fashion, the canopy of the 1 Series - unlike the 3 Series which was launched earlier this year - is of a fabric interwoven with fine shiny metallic fibres. The canopy folds open or closed in 22 seconds and can be operated at road speeds of up to 40km/h.
Even with the lid folded in, a useful 240 litres luggage space is claimed.
BMW make much of its sun reflective technology, which reduces the heating effect of UV rays on the leather upholstery by sunlight by way of deflective colour pigments worked into the material.
The 1 Series is equipped with a rollover sensor, which automatically activates rollover bars should it detect the possibility of capsize. It simultaneously activates the front seat belt tensioners and the head thorax air bags.
Andreevski says that BMW's already dizzying array of variants, far from confusing buyers, is working to the marque's advantage.
“The main focus is identifying the customer's needs and demands. We're set to reach our target of 16,800 for 2007.”