The ornamental design for a windshieldprotector, as shown and described.
FIG. 1 is a perspective view of a windshield protector showing my new new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is an opposite side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is an in-use view thereof; and,
FIG. 9 is a perspective view of the design when folded.
In FIG. 8, the broken lines showing the environmental structure for purposes of illustrating the windshield protector in a condition of use. The broken lines and the structure they depict form no part of the claimed design.