Using this Cobb airbox is easy. First, follow the included installation guide to install it on your 2018 - 2021 Subaru STI or STI Type RA. Make sure all the parts are properly connected. When using your car, the airbox will automatically draw in cold air through the factory snorkel. Just drive as you normally would. As for maintenance, check the airbox periodically for any dirt or debris. If it gets dirty, you can gently clean it with a soft cloth. Avoid using harsh chemicals as they may damage the aluminum. If you notice any issues like strange noises or reduced performance, it's a good idea to check the connections and the air duct. That's it, and enjoy the improved performance of your car!