In the near future, we expect many mobile networks (ex. vehicle in-side network, personal area network) are connected to the Internet and to the other mobile network to support rich applications for user's daliy life. There are several technology to connect these mobile networks to network and the Internet such as Mobile IP, Network Mobility (NEMO) and Mobile Ad-hoc Network (MANET). We specially investigate the use of both NEMO and MANET for efficient communication for an in-vehicle network. This paper proposes Mobile Gateway supporting policy based routing. It manages both NEMO connectivity and MANET connectivity and switches path to a destination according to application requirements and network environment. Our results shows this approach is efficient for vehicle network.