The increasing demand of diverse vehicular network oriented applications (both safety and non-safety related services would undoubtedly lead to shortage of spectral resource challenge for V2V communication networks. In order to resolve this issue, a novel Adaptive CR Enabled Vehicular NETwork (ACREVNET) framework is proposed in this paper. To avoid heavy overhead usually incurred during spectrum sensing, we developed a novel CR adaptive spectrum sensing (CRASS) scheme that can reduce the spectrum sensing cost and improve sensing performance effectively. We also applied the concept of Nash Bargaining Solution (NBS) to guarantee fairness in spectral resources allocation and proposed a generalized non-symmetric NBS (GNNBS) to perform a non-symmetric cognitive inter-cell spectrum allocation in the proposed ACREVNET framework. Simulation results clearly show that the proposed schemes can acquire additional spectral resource for vehicular communication by applying CR technology, and reduce the message transmission delay and blocking probability significantly.