[03z4]

Hi guys, 2005 x3...rear pass side of my trunk under the hard plastic storage tray was wet. I took everything out and dried the sound dampening mat. Anyway I noticed this open hole in the sheet metal essentially behind rear bumper, and noticed water in it...is this supposed to have a rubber plug etc?

Pic is sideways (rotate 90° counter clockwise for more accurate view) so upper hole with rubber grommet is above other hole and floor pan is to the left in pic (notice blue emergency case)