the triangular rubbers are to keep the door from rattling. There really is no adjustment but you can tighten the screws enough to when you close the door, the aluminium triangles on the door jambs will put them in their proper orientation, then open the door and tighten the screws. You really don’t need the shims; these rubbers were made for a wide variety of cars such as 1930s Mercedes-Benzes.
Larry Lewis