Hi. I had water leaking into my boot. Checked everything from rear wiper seal, brake light in spoiler to rear light cluster and in the end it turned out to be the seal around the fuel filler flap. The water was dripping down inside, down the inner arch and pooling inside the trim. It then overspilled into the wheel well. One Philip screw holds it in from the outside but you have to disconnect the solenoid from the inside. Tube of sealant and she’s sorted 👍