This paper proposes a parallel simulation framework for the advanced testing of connected and automated vehicle (CAV) systems. The platform integrates an orchestrator framework, open-source network and traffic simulator, and industrial Hardware-in-the-Loop system, thereby providing a synchronised environment for the study of traffic behaviours, communication delays, and vehicle dynamics. The integration of message broker services and real V2X communication processes facilitates capturing message timing and network-induced delays. The incorporation of accurate environmental modelling, including physical obstacle placement, ensures realistic representation of propagation and shadowing effects. This simulation environment enables comprehensive performance evaluation of CAV applications under various traffic and network conditions, offering insights into latency-critical scenarios. The proposed approach addresses the disparity between theoretical analysis and practical implementation, thus facilitating the development of resilient and efficient vehicle technologies through the provision of precise latency and performance measurements.