This study focused on the development of an IoT-based real-time car security and theft prevention system specifically designed for older sedan-type vehicles, which are more vulnerable to theft due to the absence of modern security features. The purpose of the system is to enhance vehicle security by enabling owners to monitor their cars remotely and receive real-time alerts about any suspicious activity. The system integrates components such as GPS tracking, cameras, and an Android application that delivers instant notifications and supports remote vehicle monitoring. The study utilized the Agile development methodology to ensure flexibility during the system design and implementation phases. This approach enabled iterative testing and continuous refinement based on user feedback. The system was evaluated using the ISO 25010:2011 software quality standards, with a group of testers that included vehicle owners. Findings indicated that the system effectively detected unauthorized access attempts, provided accurate location tracking, and automatically recorded audio and video inside the vehicle during such incidents. Users reported high satisfaction with the system’s interface and responsiveness. However, the study was limited by the small sample size and environmental factors such as network stability, which may affect the delivery of real-time notifications in areas with poor connectivity.