Spy shot of the 2021 BMW M5 CS

BMW is working on an updated version of the 5 Series that will go on sale later this year as a 2021 model.

The high-performance M5 will also be updated, this time with a new performance flagship that will be positioned above the current M5 Competition and will likely be named M5 CS in the lineup. A prototype of this flagship has been spotted.

This prototype may look like a previous tester of the updated M5, but look a little closer and you will notice some key differences.

The grille and front mask are unique to this prototype. There is also a front lip spoiler not seen on previous testers, and at the rear there is a new trunk lid spoiler, the same design used on the M2 CS, M3 CS, and M4 CS.

It is not clear what improvements have been made under the hood, but word on the street is that the M5 CS will be the first model to feature the newly developed V8 engine.

The new V-8 engine is said to be more compact than BMW's current 4.4-liter V-8 engine, but will still feature the "Hot V" turbocharger configuration and possibly other attributes of the existing engine. The new engine is also believed to be electrified, and it is possible that the M5 CS will feature a mild hybrid system or other electrification. [Peak output is expected to be significantly higher than the M5 Competition's 617 hp.

Other improvements to BMW's past CS models include weight reduction, less strict electronic nannies, and exclusive items in the cabin.

As mentioned above, the updated 5 Series is expected to arrive at dealerships later this year as a 2021 model. The updated M5, including this new M5 CS, should arrive shortly thereafter.