The integration of physiological monitoring into vehicles offers great potential for safety and comfort. Heart rate (HR) is a key vital sign, reflecting stress, fatigue, and health status. This talk provides an overview of HR sensing in cars, based on research and practical experience with in-vehicle ECG. It discusses physiological fundamentals, challenges of dynamic environments, and factors affecting signal quality. A comparison of sensor technologies—PPG, ECG, radar, BCG—highlights performance, integration, and limitations. Emphasis is placed on real-world validation beyond lab settings. The talk proposes best practices for evaluation and stresses interdisciplinary collaboration to improve system robustness and relevance. HR monitoring remains a central, complex challenge for driver state assessment and human-vehicle interaction.