The ornamental design for a golfcartseatcover, as shown and described.
FIG. 1 is a top perspective view of the golf cart seat cover showing my design as it fits on a golf cart; and,
FIG. 2 is a top view of the golf cart seat cover.
The bottom and sides of the golf cart seat cover are plain and unadorned and do not form a part of my design.
The broken lines showing flowers represent optional artwork that may be added to the design, but they are for illustrative purposes only and form no part of the claimed design.