You all have interesting calculations and confirm that the power to weight ratio is critical.
But the easy part in the equation is adding power: more and more and even more !!!
The hard part is keeping the weight low: it has huge implications on the driving feel, sizing of chassis elements (for example brake discs can be smaller) etc...
Is BMW simply going in the wrong direction ?
Cf Lotus' philosophy and Gordon Murray's latest supercar !
Even Chris Harris is trouncing Ferrari for this:
Even 100, 200 or even 500 extra horsepower on the M3/M4 will not change the laws of physics and its weight.
BMW: please refocus on the CSL concept - L is for Leicht ie Light...