The M3 features a Bootmod3 OTS E85 S55 map. That means it is not custom tuned. Boost is around 25 psi. The C63 has unknown mods but the M177 V8 is said to be tuned to 550 rear wheel horsepower which is about right but of course it depends on the quality of the tune, fuel, and supporting mods.
Unfortunately, the video does not have any sound. However, since it is a chase video anyway this is not a big deal. Not exactly high quality but you see the M3 pull away.
There is something still to be said for having a lighter and more efficient package. A traditional M3 strength.