The ornamental design for a mobilebase for infantcar seat, as shown and described.
FIG. 1 is a perspective view of the mobile base for an infant car seat from the top, rear and right showing my new design;
FIG. 2 is a side view of the infant seat mobile base from the left;
FIG. 3 is a side view of the infant seat mobile base from the right;
FIG. 4 is a front view of the infant seat mobile base;
FIG. 5 is a rear view of the infant seat mobile base;
FIG. 6 is a perspective view of the infant seat mobile base from the bottom, front and left; and,
FIG. 7 is a side view of the infant seat mobile base from the left with an infant seat mounted on the base.
The broken lines shown in the drawings are for the purpose of illustrating environmental structures or portions of the infant seat mobile base that form no part of the claimed design.