Using this OLM OG Plus Final Edition rear fog light is a breeze. First, find a suitable location at the rear of your Subaru WRX or STI 2015 - 2021. Then, use the included mounting hardware to secure the rear fog assembly in place. Connect the wiring harness with connectors to the appropriate ports in your vehicle - it's plug and play, so you don't need to be an expert. When driving, you'll notice that the parking light is dimmer than the brake light, just like in many US vehicles. The brake and reverse lights have a cool F1 - style blinking effect before going solid. As for maintenance, keep the lens clean. You can use a soft cloth and a mild cleaning solution to wipe it down. Avoid using abrasive materials that could scratch the lens. If you have any issues with the wiring or the light not working properly, check the connections first. If the problem persists, contact the manufacturer.