The ornamental design for a undercarriagewinddeflector, as shown and described.
FIG. 1 is a perspective view of the undercarriage wind deflector of the present invention, with the undercarriage showing in phantom;
FIG. 2 is a bottom elevation view thereof;
FIG. 3 is a top elevation view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a right side elevation view thereof;
FIG. 6 is a front elevation view thereof; and,
FIG. 7 is a rear elevation view thereof.
In the drawings, the dotted broken lines in FIG. 1 depict a truck, and the dashed broken lines in FIGS. 1, 2, 3 and 7 show portions of the article that form no part of the claimed design.