Using these Perrin wheel spacers is a straightforward process. First, make sure your vehicle is a 2005 - 2021 Subaru STI or a 2015 - 2025 Subaru WRX. If you're using aftermarket wheels, check that they have 0.078' deep pockets between the stud holes on the wheel mounting face. OEM 5 - spoke STI wheels are not compatible. You can expect to spend about 30 minutes on installation. During installation, take your time to ensure a proper fit. Once installed, these spacers will give your vehicle a great stance. For maintenance, regularly check the tightness of the bolts to ensure safety. Keep them clean and free from dirt and debris to extend their lifespan.