If you are buying our one piece Mustang floor pan or our passenger side rear extended floor pan, you will find they line up great until you come to the area where it meets the wheel house. The inner Wheel house is very different Mustang vs. Cougar and this used custom cut will be needed if your existing pan needs replaced all the way to the wheel houses. If you need more material than what is shown contact us with a picture of your needs and we can cut to suit.