This bracket supports the E30 air dam (also affectionately know as the “cow catcher”). These support brackets fit both “is” and “es” trim level “Series1” examples 1985-1988 (later for convertibles). Three middle brackets and two corner brackets were originally fitted, and the right, center, and left are each slightly different parts with the right and left brackets having offset bolt holes.
Each part is clearly marked “R”, “C”, or “L”. This is the right side part. The center and left brackets are also available, as well as the elusive corner support brackets.