I just don't want McLaren expanding their range like all the other performance car companies such as Porsche, Lamborghini, Ferrari etc. to accommodate loads of different cars. I think McLaren should offer three main cars, a Sports car, a Grand Tourer and a Super car.
Currently we have two Super cars, the 12C and 650S. With a Sports car (P13), and another Super car on the way (P15). I imagine McLaren will stop production of the 12C permanently within the next two years, as Ferrari will be bringing out their 458 replacement, and the 12C will not be able to compete anymore.
As much as it pains me to say it, as i prefer the 12C to the 650S, I think McLaren should scrap the 12C and make the 650S their main Super car. This way McLaren will be able to compete with Ferrari's latest, at least until McLaren release something new to compete with it. Then if they introduce the P15 as a Grand Tourer with about 700bhp, possibly make it Front Engined (SLR anybody?), then the P13 can slot below all of them as their entry level Sports car.
However, i have a feeling that the P15 will be the 12C's replacement, and will instead rival the 458's replacement instead. It is only logical, as the 458's replacement will come out around 2016.