Using this Noble Gurney Flap is a great way to enhance your Subaru WRX or STI. First, check if it fits your car as it's designed for 2015 - 2024 WRX and 2015 - 2021 STI models. When it comes to installation, pick a day with a temperature between 75 - 95 degrees and make sure this temperature lasts for at least 24 hours. Cleaning the installation area is crucial. Get rid of any dirt, debris, Armor All, or wax. Before fully installing, test fit the flap to see how it goes. Once you're satisfied, remove the backing from the double - sided adhesive, place it on the right spot, and press firmly for 30 seconds. For the best results, wait 72 hours. As for maintenance, just keep it clean, and avoid using harsh chemicals. With proper use and care, this flap will keep your car looking good and performing well.