Yeah sure they make ethernet hubs with coax on them. Have you ever heard of bnc? You need to get a hub with a bnc connector and then you need a bnc card in the car pc or you need another hub to hook the bnc to and use the other hub's rj45's to hook up the car. You will need 2 bnc t connectors, and 2 50 ohm bnc terminators to put on each end of the cable. Any questions email me.