The ornamental design for an exteriorsurfaceconfiguration of a vehicle rear light unit, as shown and described.
FIG. 1 is perspective view from the front left of an exterior surface configuration of a vehicle rear light. The drawings and descriptions represent the left side embodiment. The design also contemplates a mirror symmetrical embodiment on the right side of the vehicle. The dash line included denotes environment and is not part of the claimed design
FIG. 2 is a front elevation view thereof;
FIG. 3 is a left elevation view thereof, and
FIG. 4 is a top view thereof;
FIG. 5 is an exploded perspective view from the front right thereof; and,
FIG. 6 is an exploded front elevation view thereof.