The ornamental design for a vehicle side sill, as shown and described.
FIG. 1 is a front right perspective view of a vehicle side sill of the present invention.
FIG. 2 is a rear left perspective view of the vehicle side sill shown in FIG. 1.
FIG. 3 is a front view thereof.
FIG. 4 is a rear view thereof.
FIG. 5 is a left side view thereof.
FIG. 6 is a right side view thereof.
FIG. 7 is a top view thereof; and,
FIG. 8 is a side view of the vehicle side sill shown in FIG. 1, with the vehicle side sill mounted on a vehicle that is depicted in de-emphasized and half-tone portions so as to illustrate the structural environment that surrounds the vehicle side sill. These portions form no part of the claimed invention. More particularly, in FIG. 8 the vehicle side sill of the present invention is shown within the broken lines, and any elements shown outside of the broken lines form no part of the claimed invention, but are instead included to show environmental aspects of the claimed invention.