The ornamental design for a vehicletaillight, as shown and described.
FIG. 1 shows a front view of a vehicle taillight.
FIG. 2 is a perspective view thereof.
FIG. 3 is another perspective view thereof; and,
FIG. 4 is a top view thereof.
The ornamental design is shown in the areas shaded in a dark color. Areas shaded in a light color (i.e., the inward housing of the vehicle taillight) are for illustrative purposes only and form no part of the claimed design.