Using this exhaust system is easy. Just follow the bolt - on 3 - piece design and attach it to your 2015 - 2021 Subaru WRX or STI as per the provided instructions. When installing, make sure all the parts fit snugly and the hanger rods are properly connected like the factory setup. For regular use, enjoy the rich, powerful sound it produces. As for maintenance, periodically check the exhaust for any signs of rust or damage, especially the T304 stainless - steel parts. You can clean the exhaust tips with a mild stainless - steel cleaner to keep them looking shiny. If you notice any unusual noises or performance issues, it's a good idea to have the exhaust inspected by a professional.