Potential safety and non safety applications of vehicular network provide solutions to current traffic system. Dynamic topology of the vehicular communication network and high speed of the vehicles make it a challenging task of authenticating the users. Researchers have proposed different types of authentication mechanisms for secure vehicular communication. We propose a new and practical card-based scheme to make it possible for authentication of users and at the same time enable transactions with vehicle Service Provider (SP). Our proposed scheme provides secure communication environment while vehicle communicating with other vehicles (V2V) or communicating with road site unit (V2R). The SP is key module in vehicular business model in that it provides non safety services to vehicular users during their journey. Our proposed scheme will help solve the security and trust issues in authentication of the users while taking service from service providers.