The upcoming convertible version of the BMW i8 plug-in hybrid sports car has been spied testing.

Confirmed by BMW CEO Harald Krüger as the i8 Roadster, the new convertible is due on sale in 2018, meaning we should see it arrive as a 2019 model. Its arrival is expected to trail that of an updated version of the i8 coupe due later this year.

An i8 coupe can be seen in some of our spy shots and reveals the differences between the two body styles.

2019 BMW i8 Roadster spy shots - Image via S. Baldauf/SB-Medien

2019 BMW i8 Roadster spy shots - Image via S. Baldauf/SB-Medien

The sloping rear windshield of the coupe has been replaced by a small, vertical rear window and new engine cover. Flanking the engine cover are new cowls that flow into the individual rear wings.

The car is more of a targa than a true convertible, with its roof likely to be a removable panel that needs to be manually stowed away.

The design was first shown on the i8 Spyder concept unveiled as far back as 2012. The concept featured a two-piece roof panel.

2012 BMW i8 Concept Spyder

2012 BMW i8 Concept Spyder

The i8 Spyder, along with the updated i8 coupe, will maintain the current 1.5-liter turbocharged inline-3, 6-speed auto, and electric motor combo. However, the setup’s tame 362 horsepower and 420 pound-feet of torque output is expected to be boosted.

Battery capacity could also be increased to help boost electric range beyond the current 15-mile rating. (Performance hybrid fans in this bracket should definitely look at Acura’s NSX which comes with 573 hp and 476 lb-ft.)

We’re expecting some new technologies in the interior, too. BMW hinted at what’s possible with its i8-based i Future Interaction concept unveiled at the 2016 Consumer Electronics Show. The concept, also a convertible, featured gesture control and multiple digital displays.