Using these GrimmSpeed fender shrouds is a breeze. First, gather all the hardware that comes with the shrouds. Since they are a direct fit, you can simply align them with the existing mounting points in your 2015+ Subaru WRX/STI's engine bay. Then, attach them using the provided hardware. It's a straightforward process that doesn't require any special tools. As for maintenance, it's easy too. You can clean the shrouds with a mild automotive cleaner and a soft cloth. Avoid using abrasive materials that could scratch the powdercoat finish. When you're not using your car for an extended period, it's a good idea to keep the engine bay clean and dry to prevent any potential rust or damage to the shrouds. If you notice any loose hardware, make sure to tighten it up regularly to keep the shrouds securely in place.