The ornamental design for a childseat for motorcars, as shown and described.
FIG. 1 is the front perspective view of the child seat for motor cars;
FIG. 2 is a front view thereof;
FIG. 3 is a rear perspective view thereof;
FIG. 4 is a rear view thereof; and,
FIG. 5 is a side view thereof from the left side with the right side being a mirror image therewith.
The fragmented showing of the surface pattern on the straps is understood to repeat uniformly throughout the strap surfaces. The fragmented cross-hatching shown on the seat, seat back and headrest is understood to repeat uniformly throughout the circumscribed areas.