The hardware for Cybercab has been public for almost two years now, so September 3 is not really a hardware reveal. What actually matters is the software stack underneath it. Tesla needs FSD to run without a safety driver at meaningful scale in Austin, and the real test is whether the v15 stack generalizes to unmapped streets or still leans on geofenced routes like the existing robotaxi service. Employees riding first is smart risk management, but it also means the public won't get a real read on reliability until weeks after the event itself. The stock reaction on September 3 will probably say more about narrative than about actual deployment numbers.