We study the vehicles clustering mechanism with consideration of low-latency message dissemination in vehicular communication networks in this paper. We consider the vehicular network in which the message dissemination is assisted by the cluster head in each cluster and the road side units (RSUs). The clustering approach has to account for the presence of RSUs, as the capacity in the link between cluster head and RSU May not be sufficient to accommodate the aggregated data rate in each cluster. Overlapping clusters allow for a coordinated beamforming transmission in the vehicular network. We formulate a joint problem of beamforming and clustering for maximizing the sum rate in the network. To tackle the difficulty of nonconvex optimization in the joint problem of beamforming and clustering, a two-step approach is developed to find the overlapping clustering with rate constraints The proposed coalition formation process is shown to converge to a stable coalition structure. Simulation results demonstrate that the proposed two-step approach always satisfies the backhaul rate constraint and.