Class C vehicle communications impose demanding requirements on an underlying communication protocol. The Controller Area Network (CAN) protocol, developed for automotive applications, addresses these requirements through collision avoidance and global prioritization. In this paper, a generic workload for Class C applications is presented. The workload defines minimum requirements and provides the stimulus for a discrete-event model of the CAN. The simulations reveal the importance of proper synchronization of the periodic messages, quantify response times for messages with different priorities, and measure network operation under various speeds.