The ornamental design for a portable automobilelift, as shown and described.
FIG. 1 is a perspective view of a portable automobile lift;
FIG. 2 is a left side elevational view thereof;
FIG. 3 is a right side elevational view thereof;
FIG. 4 is a front elevational view thereof;
FIG. 5 is a rear elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines in the figures are included for the purpose of illustrating portions of the portable automobile lift that form no part of the claimed design.