I've noticed this for a little while, but haven't been concerned about it, as it seemed minor, so I kept putting off looking into it. Today, after washing the car, it seems worse than usual, so I'll have to have a look at it this weekend. Basically, there are very light streams of water that I notice down the inside of the rear window, starting at the cover for the high level brake light I inspected the top of the tailgate, in the section circled in green, and that is bone dry. The area marked in blue is where the rear boot seal meets the tailgate, so as the area in green is dry, I can only assume the water is NOT coming in through the seal Inspecting the inside of the brake light cover, it seems like most of the water is on the top right, so it looks like the water is coming in somewhere just to the right of the high level tail light, which is under the rear spoiler. I'll have to look up how to remove the spoiler to have a look at this over the weekend.