In this new chapter of Cybersecurity Under Pressure. Real Attacks, Real Lessons, we tackle the dangerous intersection of operational friction and systems engineering. A dealership laptop starts a DoIP reflash at 18:45. The authentication portal lags, the technician forces a shared session to stay alive, and suddenly the trust chain is compromised by a manual workaround. This episode challenges the "IT vs. Workshop" divide, arguing that latency, token refresh rates, and bay throughput are strict security requirements. We discuss how to architect revocation as a safety-critical OT function using transactional flows and A/B partitions, and dive into formally verifying the backend-to-bootloader handshake as a robust state machine.