Preparing Bonding Surfaces: Cleaning
WARNING: This page is about a different car, the 2021 Porsche Cayenne and 2020 Porsche Cayenne. However, it is still accessible from the selected car via links, so may be relevant.
Then, clean the bonding flange areas using a lint-free cloth soaked in isopropanol or acetone until there are no more residues on the cloth.
Leave cleaned surfaces to dry off for 15 minutes; the bonding surfaces must be completely dry.