Modern cars are really a LAN with an engine and wheels. You need to decide how secure each computer on the network needs to be or whether it is enough that you

Modern cars are really a LAN with an engine and wheels. You need to decide how secure each computer on the network needs to be or whether it is enough that you need be able to get into the car to get at the diagnostic connector. There was a case a while back of one model of car being easily stolen because the cables to the ABS system accessable from the wheel arches. There has also been talk of allowing wireless access to the in-car network in order to allow cars to be driven much closer together in high-occupancy lanes.