The rapid advancement of autonomous vehicle (AV) technology has opened up new possibilities and challenges in the domain of human-agent interaction. As AVs become increasingly prevalent on our roads, it is crucial to understand how humans perceive and interact with these intelligent systems. This workshop aims to bring together researchers and practitioners to explore the perception of cars as social agents. We explore the shift in user perception and the implications for interactions between autonomous vehicles, human drivers, and vulnerable road users (pedestrians, cyclists, etc.). Additionally, we investigate the communication of goals and intentions between cars and humans, as well as issues related to mixed agency, stakeholder perspectives, in-vehicle avatars, and human-vehicle power dynamics. The workshop aims to uncover the benefits, risks, and design principles associated with this emerging paradigm.