Recent trademark filings reveal that BMW has protected the names of a range of potential M cars wearing the CS designation. The names range from “M1 CS” through to “M8 CS.”

While it’s not unusual for automakers to trademark names even when there’s no intention to actually use them, there are rumors BMW’s M division is planning a range of hotter CS-badged cars starting with an M2 CS.

News of the car, previously thought to be an M2 CSL, surfaced in July and since then partially camouflaged M2 prototypes have been spotted testing at the Nürburgring.

Bimmerpost, citing a reliable source, claims the M2 CS will be fitted with the turbocharged 3.0-liter inline-6 of the M3 and M4 but with a slightly detuned output of 400 horsepower—still a healthy jump over the 365 hp of the standard M2. The M3 and M4 come with 425 hp in standard form and 444 hp when equipped with an available Competition Package, so there’s no issue of the M2 CS stepping on the toes of its big brothers.

The video from YouTube user cvdzijden - Supercar Video shows one of the prototypes. Its exhaust note is much closer to that of the M3 and M4 than the standard M2.

In addition to the power boost, the hotter M2 is also expected to wear carbon fiber-reinforced plastic body panels, more aggressive aerodynamic elements and potentially even carbon-ceramic brake discs. The cabin should also be stripped out to further save weight.

We just rated the standard M2 Motor Authority’s Best Car to Buy 2017, so a hotter version of an already brilliant car is just icing on the cake. Interestingly, an M4 CS is also a strong possibility.

Stay tuned for an update.