Vehicular ad hoc networks (VANETs) provide a safer driving environment by allowing vehicles to broadcast safety related messages and inform neighbouring vehicles regarding traffic and road conditions. Safety can only be achieved if transmission of messages are reliable. However, verification of reliability may violate privacy. On the other hand, it is desirable that malicious or defective vehicles can be identified and revoked. In this paper, we propose a new protocol using certificateless signature and reputation system to achieve the sometimes contradictory requirements of a reliable, private and accountable VANET message announcement scheme.