Since I started as an Ultrasport I didnt have to cut anything. But the base model A4 had some cutting that was necessary, take a look at the instructions, there are pics of what needs to be cut, just some of the plastic on the upper piece. The lower is just removed from the car so shouldnt need to cut any of it. The pics in the pdf show everything pretty clear, but you'll have to use a language converter to read the instructions.