Check whether there is a leak at the clips of the rear module panel. See Fig. 1.
The rear module panel must be flush at the rear module. If the panel is not flush and the clips are damaged, the rear module panel must be replaced. If the clips are not damaged and the panel is not flush, seal the panel with butyl, above all in radius area.
(1) Rear module panel
Water can enter the luggage compartment through the bore hole of the clip (2) for the rear module panel. There are also clips under the plate in the areas (3) and (4) and water can also enter through these holes.