The ornamental design for a speakergrill for cars, as shown and described.
FIG. 1 is a perspective view of front, top and right side of a speaker grill for cars showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear 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 broken lines shown in the drawings are for the purpose of illustrating environmental structure and form no part of the claimed design. A mesh part of a central portion of the speaker grill for cars described by the broken lines forms no part of the claimed design.