Content dissemination in Vehicular Ad-hoc Networks (VANETs) has the potential to enable a myriad of applications, ranging from advertising, traffic and emergency warnings to infotainment. This variety in applications and services calls for mechanisms able to optimize content storing, retrieval and forwarding among vehicles, without jeopardizing network resources. Content Centric Networking (CCN), takes advantage of inherent content redundancy in the network in order to decrease the utilization of network resources, improve response time and content availability, coping efficiently with some of the effects of mobility. Floating Content (FC), on the other hand, holds potential to implement efficiently a large amount of vehicular applications thanks to its property of geographic content replication, while Software Defined Networking (SDN), is an attractive solution for the lack of flexibility and dynamic programmability that characterizes current VANET architectures. By implementing a logical centralization of the network, SDN enables dynamic and efficient management of network resources. In this paper, for a few reference scenarios, we illustrate how approaches that combine CCN, FC and SDN enable an innovative adaptive VANET architecture able to efficiently accommodate to intermittent connectivity, fluctuating node density and mobility patterns on one side and application performance and network resources on the other side, aiming to achieve high QoS. For each scenario, we highlight the main open research challenges, and we describe possible solutions to improve content dissemination and reduce replication without affecting content availability.