A method of selecting primary and secondary cellular networks for a vehicle comprises measuring cellular connectivity parameters for cellular communication between a first subscriber identity module (SIM) and a first cellular network and for cellular communication between a second SIM and a second cellular network, comparing measured cellular connectivity parameters for the first SIM to measured cellular connectivity parameters for the second SIM, designating one of the first SIM and the first cellular network and the second SIM and the second cellular network as a primary network, and designating the other one of the first SIM and the first cellular network and the second SIM and the second cellular network as a secondary network, measuring cellular connectivity parameters for the primary and secondary networks, comparing the measured cellular connectivity parameters for the primary and secondary networks, switching designation of the primary and secondary network based on measured cellular connectivity parameters.