There are many changes occurring in the automotive industry regarding the usage of serial data communication, or networking. These changes are structural, technical and functional. Structural changes occur in the topology of the networks, technical changes focus on the adaptation of the existing networks, and functional changes incorporate new networks for specific applications. The progression of time, along with the desire to expand the functionality of networks in automobiles, has caused most car companies to realize that multiple independent networks are needed across a vehicle to handle specific functionality. Today there is strong agreement that there is no one single vehicle network that will fill all needs. This paper will address all the different networks and their proposed usages.