This thesis explores the development of an on-board payment solution tailored for Android Automotive, created in collaboration with Concept Engineering Reply, aiming to implement a robust application with full business logic to support secure and seamless in-car transactions. As vehicles continue to evolve from mere transportation devices into sophisticated, connected systems, the demand for integrated, driver-centric services has increased. Modern vehicles now play a central role in enhancing driving experiences by assisting with tasks such as locating parking, paying tolls, and refueling or recharging. Research suggests that drivers prefer making payments for automotive-related tasks, such as fuel or tolls, directly from their vehicles, underscoring the need for integrated payment solutions in connected cars.