What is this mystery model?
Towards the end of 2019, BMW forgot to put camouflage over an M5 CS prototype, proving that a more powerful and more track-focused version was in the works. The M5 CS, which was later spotted on the Nurburgring, is expected to feature a tuned version of BMW's 4.4-liter twin-turbo V8 engine producing at least 640 horsepower. This is more than the 617-hp rating found in the current top M5 model, the M5 Competition.
BMW has yet to reveal the M5 CS but a recent spy video has us thinking that it won't be the only CS-branded model arriving soon. A spy video recently captured what looks to be a 2020 BMW M8 Convertible out on the Nurburgring, completely disguised in camo. But the M8 Convertible is already on the market, so why would BMW go through the effort of disguising it? Unless it is a CS variant.
The BMW M8 in coupe, convertible, and Gran Coupe body styles, features a mechanically identical drivetrain as the M5. BMW currently offers the M8 in standard and Competition guises but if the M5 is getting a hardcore CS variant, it would make sense for the flagship M8 to receive one as well. This convertible prototype seems quite tame for a potential CS model but late in 2019, BMW was spotted testing a more aggressive-looking M8 Coupe prototype with a large rear wing.
All M5 and M8 models are currently powered by a twin-turbo V8 engine known as the S63. BMW is rumored to be working on an updated version of this engine, which could be called the S68. The S68 will retain the hot-V turbocharger configuration but will add some form of electrification. After seeing BMW test several models that all currently use the S63, we have little doubt that a major update is incoming.