The CP brings styling features, bucket seats, revised suspension, a sportier exhaust and bigger wheels to the party, but perhaps most importantly of all it also adds extra power to the 3.0-litre twin-turbo straight-six engine.
That means the headline output of the M3 Saloon, M4 Coupé and M4 Convertible variants climbs 19hp to a peak of 450hp, which shaves a tenth of a second off the 0-100km/h sprint on all versions, no matter whether they're fitted with the seven-speed M Double Clutch Transmission (DCT) or the six-speed manual gearbox. So the quickest examples (M3 and M4 Coupé) hit 100km/h from rest in 4.0 seconds flat, while the DCT Convertible ticks off the same benchmark in 4.3 seconds.
BMW isn't quoting any differences for economy and emissions figures on the M3/M4 CP models, with economy anywhere between 32.1- and 34mpg (8.8- to 8.3 litres/100km), and CO2 emissions of between 194- and 204g/km for the M3 and M4 Coupé, and 31- to 32.5mpg (9.1- to 8.7 litres/100km) with 203- to 213g/km on the Convertible.
Anything else?
In more detail, the Competition Package incorporates Adaptive M Suspension tuned specifically for the CP cars; recalibration of the Active M Differential and the Dynamic Stability Control; forged 20-inch M alloy wheels; lightweight M Sports seats (not on the M4 Convertible, though); seatbelts with M stripes woven into them; a sports exhaust system with black chrome tailpipes, said to be even louder and more enticing than the standard set-up; and BMW Individual high-gloss Shadow Line exterior trim, which features on the window surrounds, door mirrors, kidney grilles, side gills and the model badge on the boot.
If there is anything about this story we have not covered, you can avail of our expert advice service via the Ask Us Anything page.