The ornamental design for a motorcycle fairing vent trim, as shown and described.
FIG. 1 is a top, front, and right side perspective view of a motorcycle fairing vent trim showing my new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a right side elevation view thereof, to which the opposing left side elevation view is a mirror image.
The front surface portions, rear surface portions, and light lens of the motorcycle fairing vent trim shown in broken lines in FIGS. 1-6 form no part of the claimed design.