Using these HT Autos Side Skirt Extensions is a great way to upgrade your Subaru WRX Sedan. First, make sure you have all the included installation hardware ready. It's best to have a professional handle the installation, as they can ensure a proper fit and might need to make some minor modifications. Once installed, these extensions will give your car a more aggressive and stylish look. As for maintenance, you can clean them with regular car - washing products. Just use a soft cloth to avoid scratching the unpainted black finish. If you notice any damage, it's a good idea to get it checked out to keep your car looking its best.