Using these fender flares is straightforward. First, carefully unpack them and check for any damages. Place the front one - piece flares on your Subaru WRX or STI sedan's front fenders and mark the spots for installation. Do the same for the rear two - piece flares around the door opening. Before fitting them permanently, you need to prep the surface of both the flares and your car. This may involve sanding lightly to ensure a good paint adhesion. After prepping, do a final fit to make sure everything lines up perfectly. Then you can paint the flares to match your car's color. Remember, these are made to order, so they'll ship 2 weeks after you place the order. For maintenance, wash them regularly with mild soap and water to keep the white gelcoat looking great. Avoid using abrasive cleaners as they can scratch the surface.