Using these RokBlokz rally mud flaps is easy. First, find the existing OEM mounting locations on your 2015 - 2021 Subaru WRX or WRX STI. Then, use the included stainless - steel and rust - resistant mounting hardware to attach the 4 red mud flaps with the black logo according to the instructions. For 2018+ Premium models, you might need to make a couple of changes during installation. Remember, these mud flaps may not work with FACTORY STI REAR QUARTER UNDERSPOILERS or AERO SPLASH GUARDS. To maintain them, just wash them with mild soap and water regularly. They're built to last in extreme heat and cold, so you don't have to worry too much about the environment. With these mud flaps, your car's lower rocker panels, lower door areas, and rear bumper corners will be well - protected from rocks, tar, and debris on the road.