The high-performance sedan can rocket from 0-62 mph in as little as 3.2 seconds.
The BMW 840i Gran Coupe is the only RWD version you can have at launch.
Other updates include a carbon fiber roof for the 8-Series Gran Coupe and an M Performance package for the M135i xDrive.
The special edition harks back to an M8 prototype from the 1990s that remained a well-kept secret for two decades.
The 2020 BMW M850i xDrive Gran Coupe has a starting MSRP of $108,900.
The German car maker will display an armada of new models on the show that take place on its home soil.
The 3-Series GT and 6-Series Gran Coupe are also going away for 2020.
The twin-turbo V8 has been tuned so that it now puts out even more power than the M8 Competiton.
The 8-Series Gran Coupe will go on sale in the fourth quarter of the year from AUD $199,900.
Pricing for the 840i Coupe will start at AUD $202,900, while the Convertible is AUD $15,000 more expensive.
BMW could phase out a number of convertibles including the 2-Series, 8-Series and Z4.
The new BMW 8-Series would be both sexy and practical as a Shooting Brake.