The ornamental design for an off-road vehicle body, as shown and described.
FIG. 1 is a perspective view taken from a front, left side of an off-road vehicle body according to our design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a left side elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
Throughout the Figures, where shown, the dashed lines showing additional structure are for illustrative purposes only and form no part of the claimed design.