A light bar contains one or more rows of light-emitting diodes (LED's) in a housing which extends across substantially the entire width of a windshield of a vehicle and is narrow in width to minimize interference with visibility through the windshield. The LED's are arranged in banks generally symmetrically arrayed about the center of the length of the housing. Two of the banks, preferably equidistant from the center, are tilted in opposite directions to each other so as to project light toward the right side and left side of the vehicle. A mechanism is provided for displacing and tilting the housing and may use pivotal arms attached to the end of the housing or adjustable Z-shaped hangers attached preferably to clamps such as visor clips already on the vehicle.