As predicted, Toyota has all-but-confirmed it will produce a convertible version of its 86 sports coupe.

The Japanese giant has announced the FT-86 Open Concept will be its star attraction at next month's Geneva motor show. The company released a sketch of the concept, but our computer-generated illustration gives a clearer indication of what the drop-top 86 will look like.

Although Toyota says the concept is to "gauge customer reaction for an open-top version" of the 86, putting it into production seems a done deal. In the next line of the press release, Toyota confirms that prototype engineering assessments are already taking place.

Given the success of the coupe – both in sales and critical acclaim – a convertible is the next logical step and would fit well with Toyota's plans to try to rejuvenate its image, after years of being considered conservative.

Although no mechanical details of the car were given, it is unlikely to depart from the same set-up that has made the coupe so popular. A soft-top roof is the most likely choice, as Toyota will want to keep weight, cost and complexity down.

Launching the 86 convertible would pitch the car directly against the Mazda MX-5, which has been the most successful Roadster in the world over the past two decades.

An all-new MX-5 is expected in 2015 and will be built in partnership with Alfa Romeo, which will resurrect the Spider nameplate for the new model.

Subaru hasn't made any announcement about a convertible BRZ, but given the co-development with Toyota on the coupe, Subaru would likely be in a position to add the convertible as well.

Toyota has also confirmed it will have two concept versions of the new RAV4 on show in Geneva. The design studies will be known as RAV4 "Premium" and RAV4 "Adventure".