Under the bonnet, the M4's 3.0-liter twin-turbocharged straight-six engine has been tweaked with the inclusion of water injection technology, which debuted earlier this year in the M4 MotoGP safety car.
The revised motor now develops 368kW of power and 600Nm of torque, an increase of 51kW and 50Nm over the standard M4. Drive is sent to the rear wheels via a seven-speed dual-clutch transmission with a standard launch control function.
Weight has been reduced to 1510kg, according to the DIN standard, thanks to the use of carbonfibre-reinforce plastic (CFRP) for the GTS' bonnet, front splitter, roof, rear spoiler, rear diffuser, and instrument panel bracing tube. The Bavarian company has also removed the M4's rear seats.
According to BMW, the M4 GTS is good for a a 0-100km/h time of 3.8 seconds, an electronically limited top speed of 305km/h, and a Nurburgring Nordschleife lap time of seven minutes 28 seconds. The regular M4 is capable of finishing the 0-100km/h dash in 4.1 seconds.
BMW says that the GTS' sports exhaust system, with a titanium muffler and 80mm diameter tips, has an "emotionally-rich soundtrack".
The car rides on new lightweight alloy wheels with orange highlights. Up front the GTS has 19-inch rims paired with 265/35 Michelin Pilot Sport Cup 2 tyres, while out the back there's 20-inch units with 285/30 rubber. M has also tweaked the car's adjustable suspension setup and revised the car's anti-roll bars.
Stopping power is provided by standard carbon ceramic disc brakes with six piston callipers at the front, and four piston units at the rear.
The M4 GTS is easy to pick out thanks to its orange highlights, large strut-mounted rear wing, prominent front splitter, blacked out grille, and OLED headlights, which made their premiere in the M4 Iconic Lights concept earlier this year.
Inside there's carbonfibre bucket seats covered in a mix of Alcantara and leather, lightweight door panels with simple door pull loops, and Alcantara and orange highlights throughout.
Optional features include a six-spoint safety harness, fire extinguisher and an uprated Clubsport roll bar. Production of the M4 GTS will be limited to just 700 units worldwide.
BMW Australia has told CarAdvice that while it is keenly interested in local availability for the M4 GTS, it has yet to confirm supply.
With just 700 units available, though, it's likely that only a very small number would come to Australia, if at all.
Click here to see more photos of the BMW M4 GTS.