This time last year, BMW graced the M3 Coupe with a series of enhancements that transformed it into the road-going M3 GTS track monster - as though the regular M3 Coupe were not already respected for its circuit abilities.
Now, those same tweaks have made their way to the M3 Sedan in the form of the M3 CRT - which means Carbon Racing Technology, and has nothing to do with the old computer screen you left on the nature strip last year.
Like its two-door GTS sibling, the M3 CRT benefits from that perfect combination of more power, and less weight.
The M3's 4.0 litre V8 engine has had its displacement increased to 4.4 litres and, along with a more advanced tune, the engine now produces 331kW and 440Nm of torque - up 22kW and 40Nm.
Weight savings come thanks to the use of carbon fibre-reinforced plastics (CFRP) in the driver and front passenger seats, the front air dam and the rear spoiler.
There's also a carbon fibre bonnet and roof, and an "extremely lightweight" titanium muffler. In all, BMW has shaved 45kg from the M3.
The combination of more power, less weight and a seven-speed M-DCT dual-clutch transmission gives the M3 CRT a 0-100km/h time of 4.4 seconds - right on par with the M3 GTS Coupe. Top speed is electronically limited to 290km/h.
The M3 CRT rides on 19-inch light alloy wheels, backed by six-piston fixed-calipers on 378x32mm front discs, modified suspension and a track-specific version of the company's Dynamic Stability Control.
The bad news? only 67 of the M3 CRT cars will be built: and they're all staying in Europe.