When Porsche comes up with a GT4 version of a car you can be sure that they will use this model in racing too. During a testing day of Porsche on the track of Monza, someone captured this Porsche Cayman GT4 which is pushed to the limit on the track.
The car is a bit lower than the standard Cayman GT4 and also fitted with more lightweight racing wheels with slicks. Also we can hear that the exhaust sound isn't damped anymore. The driver is really pushing the Cayman to the limit as we can see around 0:50 in the movie where the driver almost loses control of the car.