The ornamental design for a vehicle side-window sun shield, as shown and described.
FIG. 1 is a perspective view of the vehicle side-window sun shield showing my new design;
FIG. 2 is a back view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top side view thereof;
FIG. 7 is a bottom side view thereof; and,
FIG. 8 is a side perspective view thereof.
The broken lines shown throughout the figures represent environment elements that are for illustrative purposes only and form no part of the claimed design.