Ideally, the network would consist of cheap wireless routers (Linksys WRT-type) mounted on each vehicle. From there, tablets or other wireless devices could connect to the router. When the vehicles are in the station, the routers would auto-connect to the WiFi network to receive calls for service and other updates. When out on a call, the router would form an ad-hoc network with other vehicles on the scene. If a vehicle came into range of an Internet "hotspot", it would notify other vehicles and become a gateway for the rest of the "ad-hoc" networked vehicles.
I've looked at Freifunk for this, but would like some other options. Recommendations please?