Along the sides of this M4 are more aggressive side skirts which have been sculpted to allow for air channels pointing to improved aerodynamics, likely for track purposes.
Out the back are where the most obvious changes have been made, with a massive rear wing sitting atop the bootlid, along with an additional lip spoiler.
Further down, extra fins have been added to the diffuser, though these look like very early versions of what will become the final product.
The additional aero kit is not dissimilar to that of the M4 GTS and the 2010 M3 GTS, however the most recent version was only launched this year, and the extended side skirts and rear diffuser additions hint that an even more hardcore version is on the way.
A possible conclusion could be that this car is the road-going version of the recently-teased M4 GT4 race car that is scheduled to hit the track for the 2018 racing season.
It could also be a road-going track special to celebrate BMW’s back-to-back 2014 and 2015 manufacturer titles in the Deutsche Tourenwagen Masters (DTM) racing series which were both won by M4 DTM race cars.
Interestingly, this prototype doesn’t appear to have any of the upcoming ‘Life Cycle Impulse’ (LCI) updates that were spied on a 2017 M4 development vehicle recently. However, this is likely to be a very early version of the production model, so plenty can change between now and when the car is launched.
With the M4 GT4 race car due to hit the track in 2018, it’s likely the production version of this prototype will debut in the lead-up to the track car’s launch.
Click the photos tab for more images of the BMW M4 GT4