Using this fender flares kit is a great way to enhance your Subaru WRX or STI. First, check your vehicle's model year to make sure it's compatible. If you have a 2008 - 2014 STI Hatchback, you'll need to cut about 40mm from the rear of the back flares. When installing, it's best to get a professional to do it. They'll take care of any necessary trimming of the factory metal bodywork and the flares for proper clearance. The kit comes with all the hardware you need for installation, like screws and double - sided tape, but you'll have to get your own tool for the rivnuts. After installation, your car can run wider over the stock wheel/tires. To maintain it, just wash it regularly with mild soap and water. Don't use any harsh chemicals as they might damage the solid polyurethane plastic. Remember, returns are not accepted for this kit, so make sure you're ready to install it.