shorting bars 44 may be deposited along with the heating conductors 36 and bus bars 40 the grid patterns of the present invention may be advantageously installed either in wire form or as deposited enamels or ceramics at several locations to be effective in heating the lower section 32 of the automobile glazing unit 12 and the parking position area of the windshield wiper blades the grid patterns may be placed at the interior surface 20 the exterior surface 26 or they may be preferably disposed within the automotive glazing at the first middle surface 22 the second middle surface 24 or installed directly into the intermediate layer 18 all that is required is that the grid pattern 34 be in thermal contact with an area of an automobile glazing unit it is recognized however that placement of the grid pattern at the interior surface 20 the first middle surface 22 the second middle surface 24 or the interior of the intermediate layer 18 avoids the harmful effects of direct weather conditions associated with mounting the grid pattern to the exterior surface 26 of the automobile glazing unit 12 in a preferred embodiment the heating conductors 36 of grid pattern 36 are shown in cross section in.