The ornamental design for a side extrusion for roofrack, as shown and described.
FIG. 1 is a top perspective view of a side extrusion for roof rack 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 side extrusion for roof rack is shown with symbolic breaks in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.