No authentication. The only sort of authentication token is linearly predictable and printed in plain text on the outside of the car.<p>No rate limiting. They successfully used the linear nature to collect a list of valid VINs and validate them.<p>No apparent intrusion detection.<p>Bad response to security disclosure. They didn&#x27;t fix the problem when it was reported, they still haven&#x27;t addressed the researcher properly.<p>I&#x27;m not sure these are the right people to write life critical software (which admittedly, this vuln. does not appear to relate to life critical systems; just privacy and comfort).