I claim the ornamental design for headlights for a vehicle, as shown and described.
FIG. 1 is a front perspective view of headlights for a vehicle, showing my design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a back perspective view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof; and,
FIG. 7 is a top view thereof.
The additional views of the headlights for a vehicle not provided herein do not provide any additional claimed features of the design and thus are not represented. The broken lines are included for illustrating environmental structure and form no part of the claimed design.