A vehicular signal mirror includes a reflective mirror element comprising a mirror reflector on a light-transmitting substrate. The flow control modules may be implemented within a sender andor receiver or may be deployed into a network as a separate device without requiring significant additional resources. The front face of each frame profile facing towards the cavity is covered by a low permeability sealant. Alternatively, the system includes a pair of order books, a workup order book and a FIFO order book. The FVs may be compared and difference determined.