A turn indication system for a vehicle includes an indicating member movable between a first position and a second position in response to the actuation of a turn signal switch. A door-ajar indication system for a vehicle includes an indicating member movable between a first position and a second position in response to the actuation of a switch so as to indicate an ajar condition of a door of the vehicle. A traffic observation system for a vehicle includes a wave receiving member for mounting to the vehicle such that the wave receiving member is oriented along a line of sight from an object approaching the vehicle from a lateral direction generally perpendicular to a path of motion of the vehicle, permitting a driver of the vehicle to perceive the object via a wave received by the wave receiving member from the object along the line of sight.