In this paper, we proposed a K-hop bandwidth aggregation scheme for member-based cooperative video streaming over the hybrid vehicular networks consisting of DSRC ad hoc network and 3G/3.5G cellular network. Each member in the same group is known to each other, e.g., they may be a family or a group of friends driving their sedans and they set out from the same position along the same path to the same destination during the journey. When a member in a vehicle wants to watch video during traveling, he will request video through 3G/3.5G network. However, the limited bandwidth of the 3G/3.5G network is not enough to support higher resolution or higher quality of downloading video. In order to enhance the quality of video playback, the member, who is called requester, in one vehicle can ask members, who are called helpers, of the same group in other vehicles to cooperatively download video through their 3G/3.5G networks and then forward their downloaded video to the requester through the DSRC ad hoc network. In order to select suitable members as helpers to download and forward the video and make video streaming more effectively to the requester over the DSRC Ad hoc vehicular network, how to select suitable helpers to forward the downloaded video hop-byhop back to the requester needs to be resolved. In this paper, we proposed a K-hop bandwidth aggregation scheme to tackle the aforementioned problem. The performance results show that our proposed scheme can get better quality video than cooperative video streaming schemes without the deliberately designed K-hop bandwidth aggregation mechanism.