This study proposes a novel framework for analyzing Vehicle-Integrated Photovoltaic (VIPV) systems, integrating optical, thermal, and electrical models. The model modifies some already existing fixed PV system methodologies for VIPV applications, to assess received irradiance, PV module temperature, and electrical energy production; it is available as an open-source MATLAB tool, enabling simulations via a smartphone. A key innovation is the integration of meteorological data and real-time driving, dynamically updating vehicle position and orientation every second to compute irradiance. Different time resolutions are explored as alternatives to high-frequency simulations to optimise computational efficiency. Additionally, the thermal model, enhanced by vehicle speed and wind effects, and thermal inertia, significantly improved temperature and power output predictions. Furthermore, the study examines the impact of passenger load and operational scenarios on energy production and consumption, providing a comprehensive evaluation of VIPV system performance. Sustainability assessments compared VIPV integration in electric and internal combustion engine vehicles, highlighting its potential to reduce emissions, as a first step towards a future comprehensive life cycle assessment. The framework has been applied to a minibus case study at the University of Palermo campus. The obtained results are analysed and discussed, enabling the validation of the proposed approach.