With the development of vehicular networks, new types of networking services arise for automotive users. Since vehicles have high mobility, it is difficult to keep stable and reliable network connections between vehicles. With regard to multi-media streaming services, a vehicle may not have good QoS of video streaming using a single 3G/3.5G wireless interface. This paper is motivated to investigate the cooperative streaming sce-nario in a fleet-based vehicular network. When a vehicle requests a video stream encoded in H.264/SVC from the Internet using its 3G/3.5G network, it asks for nearby vehicles belonging to the same fleet to download the requested video data cooperatively through these nearby vehicles' 3G/3.5G network and then forward these downloaded video to the requested vehicle through V2V Dedicated Short-Range Communication (DSRC) networks. Since the topology of a vehicular network may change dynamically, an adaptive video transmission scheme is utilized to control the sending rate of the server to avoid the congestion of vehicular networks and retransmit the lost video to the requester to improve the quality of video before the playback deadline. We utilize EstiNet Network Simulator and Emulator (NCTUns) to simulate the proposed schemes. Based on the simulation results, the proposed priority first retransmission scheduling (PFRS) can have higher PSNR values in the network condition with lower Bit Error Rates (BER) and the dependency cost retransmission scheduling (DCRS) would have higher PSNR values in the network condition with higher BER.