The ornamental design for an underbar for roofrack with aperture/window, as shown and described.
FIG. 1 is a top perspective view of an underbar for roof rack with aperture/window showing the new design.
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a bottom view thereof; and,
FIG. 6 is a side view thereof.
The underbar for roof rack with aperture/window is shown with symbolic breaks in its length. The appearance of any portions of the article between the break lines forms no part of the claimed design.