The ornamental design for an infantcarseatboot, as shown and described.
FIG. 1 is a forward perspective view of the infant car seat boot showing my new design;
FIG. 2 is an elevational view from the lowermost end thereof;
FIG. 3 is an elevational view of the opposing vantage of that shown in FIG. 2 viewed from the uppermost end thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a top plan view of the infant car seat boot;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is forward perspective view of the infant car seat boot in an alternate position; and,
FIG. 9 is a forward perspective view of the infant car set boot in another alternate position.
The broken line showing of portions of the infant car seat boot is included for the purpose of illustrating environmental structure and forms no part of the claimed design.