Water Getting into Interior

[ChiefRider]

I am getting water in the rear passenger side footwell after a rainstorm. I have recently sealed my pano sunroof with vinyl paint protection film; that appears to have been successful as water was getting in everywhere prior to that, and the film is well intact around the sunroof.

A few years back, I did have the adjacent door panel off, and took great care to ensure the inner panel was well sealed at every point before replacing the door panel. My X5 has no rust, and the water incursion takes place overnight when parked. I will likely go back into the door, but thought I would ask, thanks!