A rain shield device includes a housing for attaching onto various vehicles, and a shield extendible out of the housing for shielding the upper portions of the doors of the vehicles and for allowing the drivers and the passengers to easily open or receive the umbrella while boarding or moving out of the vehicles. The shield may be extended out of the housing with two links and two racks and a motor. A shaft is rotatably received in the housing for winding and receiving the shield, and may be rotated relative to the housing by a motor.