The ornamental design for a frontportion of an automobile, as shown and described.
FIG. 1 is a front perspective view of a portion of an automobile showing our new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a right side elevation view thereof, the left side being a mirror image thereof;
FIG. 4 is a front elevation view thereof;
FIG. 5 is a rear elevation view thereof; and,
FIG. 6 is a top plan view thereof.
The portion of the automobile in light contrast is environment and forms no part of the claimed design. The bottom view of the front portion of the automobile forms no part of the claimed design.