Hello Together, I have already noticed repeatedly that when driving in bad weather or over dirty roads in the interior at the rear doors (wheelbox cutout) a real “crust” is formed relatively quickly. Had I before in the form with no other car. Does – if one does not open the rear doors – not at first. Also I have the impression that in the rear interior area, especially where the wheelbox cutout is, in the ground area at the rear seat very quickly always form a kind of dust layer. Why ever. The basic tightness of the interior I would actually assume. As I said, it is a kind of fine dust. No moisture. Especially when one opens the rear doors and looks at the ground (where the seat runs into the area of the wheelbox cutout. There it collects) It also seems that when model collation has at least made similar experiences. So I have now found this mailing from the summer of 2021: Quote: @Molist wrote on the 1st of June 2021. At least there is no guarantee.