Using these floor liners is a breeze. Just place them in your 2015 - 2021 Subaru WRX or STI footwells. Make sure they fit snugly and use the retention system to keep them in place. When cleaning, simply remove the liners from your car. You can wash them with soap and water and let them dry. Avoid using harsh chemicals as they might damage the high - density material. Also, check the liners regularly for any signs of wear and tear. If you notice any issues, replace them to keep getting the best interior protection and maintain your car's resale value.