It should debut before the end of the year.

A new spy video (embedded below) provides a look at the upcoming BMW M5 CS, including a peek into the engine bay and the cabin. There's not a bit of camouflage on it except for some protective covering over the front seats.

This M5 CS wears a satin black body that gives the exterior a subtly aggressive appearance. It rides on matching wheels with V-shaped spokes. The CS badge is visible on the front fender outlet trim as the camera sweeps over the side of the sedan. The clip also shows off carbon fiber mirror caps and a thick-rimmed, Alcantara-covered steering wheel.

 

Earlier spy shots showed the M5 CS with a slightly different exterior. That one had copper-colored wheels and a small trunk lid spoiler. It was also easier to see the lowered suspension. Other tweaks allegedly include ceramic brakes and a CFRP roof.

The Instagram post says the model packs 650 bhp. Assuming this is a reference to metric horsepower, then it fits perfectly with an earlier rumour of the M5 CS making 641 bhp (478 kilowatts or 650 PS). The engine is allegedly a tuned version of the regular M5's 4.4-litre twin-turbo V8 that produces 616 bhp (460 kW) in the existing Competition model.

With extra power, the M5 CS should shave a few tenths off the standard model's ability to reach 60 miles per hour (96 kilometres per hour) in 3.1 seconds. The suspension tweaks and ceramic brakes should make the saloon sharper in the corners, too.

Gallery: BMW M5 CS

The M5 CS will reportedly debut before the end of the year. Seeing this completely finished example suggests that these rumours are accurate. The CS' extra performance parts mean the price would be even higher than the £98,095 price for the 2021 M5 Competition.