Nah, it will still be an extremely even competition and the wins will be shared equally around the brands. In all honesty the whole COTF thing is just a promotional gimmick - all 4 brands of cars will run IDENTICAL floor pans, suspension, brakes, wheels, steering, ECU, engine position/weigh balance, trans, diffs, etc etc. And they will be tuned to the EXACT same kw - with the Nissans being severely restricted so as to not make too much power.
Really they will all the be exact same cars, with different body shells on top
Already the Ford and Holden camps have been whinging about Nissan having an unfair advantage, as in early testing the Altima had a better wind/drag coefficient, and last I heard they were making Nissan put some flatter panels on the intakes of the Altima to somewhat mess up the drag coefficient to make it equal to that of the Fords and Holdens.