A convertible version of the BMW i8 plug-in hybrid coupe was teased as far back as the 2012 New York Auto Show, when the i8 Spyder concept first debuted.
But while the i8 coupe went into production as a 2014 model, BMW has been unusually slow to approve a convertible version for production.
BMW mentioned an i8 convertible during a March press conference, but now it appears the drop-top i8 won't arrive immediately.
The i8 convertible won't arrive until 2018, BMW CEO Harald Krueger said in a recent interview with Reuters.
This means the convertible could arrive after a mid-cycle refresh of the i8, which is expected to occur some time in 2017.
When it does appear, the i8 convertible will likely adopt the Spyder name of the original 2012 concept.
BMW i8 Concept Spyder
In addition to that show car, BMW unveiled a second i8 convertible concept—the i Future Interaction—at the 2016 Consumer Electronics Show.
Adding a convertible version late in the product cycle would help reinvigorate interest in the i8, which made quite a splash when it went into production late in 2014, mostly thanks to its sexy styling and "bird-wing" doors.
The i8 convertible likely won't have much direct competition.
The only plug-in convertible currently sold in the U.S. is the tiny Smart ForTwo Electric Drive battery-electric car.
Beyond the addition of the convertible body style, the i8 is expected to get a significant mechanical update in the near future.
This could include increased power and electric range, the latter courtesy of a higher-capacity battery pack.
BMW i Future Interaction concept - 2016 Consumer Electronics Show
BMW could also add wireless charging similar to the Qualcomm system currently used in the i8 pace cars of the Formula E electric-car race series.
Reports earlier this year also indicated that BMW plans to build an all-electric i8 prototype.
This vehicle would be used to test an all-electric powertrain for the coupe, but wouldn't necessarily go into production.
BMW has also used the i8 as a test bed for hydrogen fuel-cell powertrains, which it likely won't deploy in production models for another few years at least.