This genuine-style water gutter is designed for the sunroof system of BMW E39 models. Sunroof Drain Channel / Sunroof Water Gutter. 520 d (E39) M 47 D 20 1951 136 100 02/00 06/03. 520i (E39) M 52/54 B 22 2171 170 125 09/00 07/04.