As far as I have played Need for Speed until today, I can replace any vehicle with another. But all the searches I have done online do not show me anything that shows how to replace or add cars. For example, search, "replace mclaren mp4 into a bugatti veyron supersport". It says something about 'supercars pack' but I didn't find it for PC to download. Can someone give me directions on where to find this, and how to install it, please?