A cloud radio access network deployed on top of edge networks as a software-defined radio access network architecture has been regarded as a promising paradigm for the next generation mobile networks, but it has not received considerable attention in the vehicular industry due to distinct design needs. For mobile networks, infrastructures provide powerful computation capability for universal radio resource optimization, and therefore an inherent cloud-down design is favorable. On the contrary, to deploy vehicular technologies, sophisticated processing capability has been a baseline feature for the next generation driving machines, which may not solely rely on wireless infrastructures to guarantee driving safety, so an edge-up design is preferred. Consequently, this article surveys the recent works on software-defined vehicular networks and proposes a series of edge-up software-defined networking designs, particularly emphasizing the most crucial function of latency control to support possible wireless applications for the next generation driving machines. The proposed designs thus create a paradigm shift to enable software-defined mobileedge vehicular networking.