The ornamental design for a plankextrusion for roofrack, as shown and described.
FIG. 1 i is a perspective view of a plank extrusion roof rack showing our new design.
FIG. 2 is a front view thereof, the rear view being a mirror image.
FIG. 3 is a side view thereof, the opposite side being a mirror image.
FIG. 4 is a top view thereof; and,
FIG. 5 is a bottom view thereof.
The broken lines in the drawings represent portions of the plank extrusion for roof rack that form no part of the claimed design. The plank extrusion for roof rack is shown with a symbolic break in its length. The appearance of any portion of the plank extrusion for roof rack between the break lines forms no part of the claimed design.