The ornamental design for a reversemirror auxiliary lighthousing, as shown and described.
FIG. 1 is a top, front, left perspective view of a front grille showing the claimed design;
FIG. 2 is a top, rear, left perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
Any shading and cross-hatching are not features of the design but are utilized to illustrate the surface contours of the design in the drawings. The broken lines in the Figures are for illustrative purposes only, and form no part of the claimed design.