As soon as it was announced as a concept in 2009, the sports car built jointly by Toyota and Subaru that we know as the Scion FR-S and Subaru BRZ twins seemed ripe for a convertible variation. Today, Toyota revealed its concept for the FT-86 Open ahead of the Geneva Motor Show, and while it's not given the green light yet, there's nothing that would stop it from losing its top.
Toyota says no mechanical or dimensional changes were made to the underlying car, which has won fans around the world for its well-balanced handling; cutting the roof off might even further lower the center of gravity which already matches that of a Lamborghini. But Toyota does say it hasn't finished the engineering work necessary to ensure the power folding top doesn't ruin the chassis' rigidity, or that it can solve any such problem without adding unnecessary weight compared to the coupe.
The biggest barrier to a production convertible may be success; Subaru can only build 100,000 FR-S/BRZ/GT86 cars a year, and so far demand worldwide seems far stronger than supply.