Using these HT Autos fender flares is a great way to enhance your 2015 - 2021 Subaru WRX/STI. First, make sure to get them installed by a professional as minor modifications may be required. Once installed, they'll expand your car's width, adding a more aggressive and sporty look. To maintain them, simply wash them regularly with mild soap and water. Avoid using harsh chemicals as they can damage the polyurethane material. Also, check the hardware periodically to ensure it's tight and secure. If you notice any signs of wear or damage, contact the manufacturer for advice or replacement parts.