Using the Hella horn kit is straightforward. First, make sure your vehicle is turned off. Then, find a suitable place to mount the bracket using the included mounting hardware. Connect the wiring harness to the horns and your vehicle's electrical system following the instructions. The plug - and - play design makes it easy for you to install without any complex wiring. Note that this kit does not fit the WRX GT model, so double - check your vehicle model before installation. For maintenance, keep the horns clean and dry. Check the wiring connections regularly to ensure they are secure. If you notice any unusual sounds or the horns stop working, check the electrical connections and consider replacing any damaged parts.