The ornamental design for a wheel trim for a vehicle, as shown and described.
FIG. 1 is a front view of a wheel trim for a vehicle according to the design;
FIG. 2 is a right, top perspective view thereof;
FIG. 3 is a left, bottom perspective view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a rear view thereof.
The broken lines in the drawings and the lightened and de-emphasized areas within the broken lines illustrate portions of the wheel trim for a vehicle that form no part of the claimed design.