wall vertical panel 14 1 as is one leg of a metal wind guide plate 9 7 the guide plate 9 7 is bent at a right angle and subdivides the space enclosed by the angle bracket 9 4 the outside panel 14 3 and the support 9 6 into a chamber 9 10 and a u shaped air channel 9 11 secondary air openings 9 2 are formed in the left hand vertically extending leg of the u shaped support 9 6 and are arranged similar to the primary air openings 9 1 but have a greater cross sectional area than the primary air openings the flange at the upper end of right hand leg of the u shaped support 9 6 is fastened underneath the car ceiling board 9 5 an horizontally extending wall of the support 9 6 is attached to an upper surface 11 1 of the lamp 11 the wind guide plate 9 7 and an inside surface of the quarter round outside panel 14 3 are covered by a damping material layer 9 8 the left hand leg of the u shaped support 9 6 and a portion of the outside car wall vertical panel 14 1 define a vertical air channel 9 12 with an air inlet opening 9 3 the opening 9 3 is bounded at the left by an upper edge of a mounting 10 1 for the internal panelling 10 and at.