The ornamental design for a pair of taillight mounts, as shown and described.
FIG. 1 is a perspective view of one of a pair of tail light mounts showing my new design;
FIG. 2 is a rear view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The other one of the pair of tail lights mounts not shown is a mirror image of FIGS. 1 through 7. The broken lines shown in the drawings illustrate environmental subject matter which forms no part of the claimed design.