content: I would have thought (hoped) that the regulation around the OS of your car would be covered by the same laws that decide if your car is road legal. Does it have working break lights, indicators, tires with grip etc. Some basic performance benchmarks could be included, system reaction times to events, rate of acceleration and that kind of thing could all be tested in simulation as part of your MOT (or local equivalent)  The problem with catching people who have jailbroken cars is that it would be fairly simple to revert the cars software back before a test happens, nobody would know until a crash happens.