In Vehicular Ad hoc Networks (VANETs), access control and authentication are crucial security services for both vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communications. On the other hand, services provided by VANETs would be reduced if the vehicle private data are misused and the privacy is not protected. In this paper, we investigate the secure access control with authentication issues and privacy preservation in VANETs. We propose a Vehicle authentication protocol based generation certification system which uses RFID tags and RFID readers deployed on the roads and vehicles. Moreover, a QoS aware node attachment and mobility management scheme is proposed.