BMW engineers have been caught testing the 8 Series in convertible form with thin camouflage, showing the soft-top's shape in better detail than before.
Seen during winter tests in the Arctic Circle in the same week images of the coupé leaked online via BMW blog Bimmerpost (see image below and gallery), the model features a flatter tail than the hardtop behind its electric folding fabric roof.
The 8 Series, which is due on sale this November as rival to the two-door Mercedes-Benz S-Class and Bentley Continental GT, is inspired by the Concept 8 Series. It also shares some exterior design features with the 6 Series.
Underneath, the upcoming flagship is technically related to the 7 Series saloon. It will essentially be a two-door coupé version of that car, much in the same way that the 4 Series and 3 Series are related.
Being so closely related to the 7 Series, it's likely that the 8 Series will share naming conventions and engines with its saloon sibling. This means that an iPerformance-badged plug-in hybrid will feature in the range, while the entry-level 3.0-litre six-cylinder diesel found in the 730d will be used in an 830d. The 8 Series line-up will also likely include the more performance-oriented 4.4-litre V8 in the 750i xDrive, accompanied by all-wheel drive. A V12-engined model will come later in the 8 Series' life cycle.
The most hardcore variant of the 8 Series will come in M8 form, with its own more aggressive bodywork. This model is likely to be powered by an uprated version of the latest M5's 592bhp 4.4-litre twin-turbocharged V8 engine and share the same M xDrive four-wheel-drive system.
Inside, 8 Series models will feature the same top-end technologies found in the 7 Series, including the latest and next-generation semi-autonomous functions.
As part of BMW's range shake-up, the 8 Series coupé will indirectly replace the 6 Series coupé, which will end production in 2018, while the 6 Series convertible will then be indirectly replaced by the 8 Series convertible the following year.
The final 6 Series variant, the Gran Coupé, despite running out at the same time as the convertible, is unconfirmed for replacement but could be renewed. Meanwhile, the 5 Series GT has been replaced by the 6 Series GT.
It might not be the end of the road for the 6 Series coupé and convertible variants, though, as BMW is still undecided as to whether direct replacements for the two will be introduced.
Additional reporting by Greg Kable
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