Detection and signalling system and method for a vehicle

A system 101 for a vehicle 100 for responding to a body 110 being detected proximal to the vehicle, comprises signalling means 102, 108 for providing a signal, the signalling means having a high resource consumption characteristic in relation to a finite system resource (e.g. stored electrical energy, computational processing capacity, or data storage capacity). The system also comprises detection means 104 for detecting a body proximal to the vehicle, the detection means having a lower resource consumption characteristic than that of the signalling means. The system is operable in: a first mode in which the detection means is active; and a second mode in which the signalling means is activated in dependence on the detection means detecting a body proximal to the vehicle. The signalling means may comprise telecommunications device for transmitting data to a remote device, e.g. for sending live video to a driver's mobile device. Also provided is a corresponding controller for a vehicle and a method.