This paper deals with formation control strategies based on Virtual Structure (VS) for multi-vehicle systems. We propose several control laws for networked multi-nonholonomic vehicle systems in order to achieve VS consensus, VS Flocking and VS Flocking with collisionavoidance. First, Virtual Vehicle for the feedback linearization is considered, and we propose VS consensus and Flocking control laws based on a virtual structure and consensus algorithms. Then, VS Flocking control law considering collision avoidance is proposed and its asymptotical stability is proven. Finally, simulation and experimental results show effectiveness of our proposed approaches.