I'm pretty sure you need parts #4, but I'm not sure what #5 is. I ordered the entire kit from OutMotoring, and I used everything that they included, except a bunch of the hardware, which I was able to re-use from my car. Of course, my car only had a couple hundred miles on it at the time (it was brand new) so the existing hardware was like new, also. I did it over two years ago, so I don't remember every detail (my car is a 2022, picked up New Year's Eve of 2021). Did I mention that I had to replace both rear wheel arches, since the SE ones were too short?