The unconfirmed but inevitable BMW M4 CS has been spied tackling the Nurburgring alongside its four-door M3 CS sibling. Finished in a striking burgundy hue, the M4 CS looks outstanding, but when will it finally be revealed, and what can we expect?

A Competition Sport version of the BMW M4 has not been explicitly confirmed, but BMW M boss Frank van Meel did concede late last year that there is room for such a vehicle below the range-topping CSL. But when exactly it will be revealed is a mystery. While the F8X generation of CS models saw the M4 unveiled first in 2017 and the M3 arriving in the following year, that script is apparently being flipped for the G8X series.

BMW M confirmed last week that the M3 CS sedan would debut this month at the 24 Hours of Daytona. Curiously, BMW did not mention the M4 CS at all, which suggests that this coupe is not being rolled out for a little while yet. Then again, BMW could surprise us and reveal both at once. Whatever the case, we can see rear seats in the test vehicle spied here, which confirms that the M4 CS won't go on as extreme a diet as the CSL. However, we expect that it may offer the same output from its S58 twin-turbocharged 3.0-liter straight-six.

According to internal documents leaked last year, the M3 CS sedan will produce 543 horsepower, which is what you get in the M4 CSL coupe. Historically, the M4 CS and M3 CS shared power figures, and if that's the case here, then perhaps BMW has chosen to delay the launch of the M4 CS a little to prevent the new arrival from stepping on the toes of its big brother.

In a straight line, the M4 CS should be even quicker than the CSL. The same leak says that the M3 CS will feature M xDrive AWD, and since the coupe version is almost guaranteed to be mechanically identical, the M4 CS should be able to out-launch its Leichtbau relation.

With so little camouflage on the test car spied here, we expect to get the answers to all our questions very soon.