Water in my passenger side floorboard

[G-Man]

My 91 318i 4 door has some water on the passenger side floorboard after some recent rains. I can't figure out where the water is coming in from. No water in the glovebox, no water stains around the sunroof, window gaskets look decent. Car was not driven in the last two weeks, just sat outside. Yes the windows and sunroof were closed. Need some ideas of where the water might be coming in from.

G-Man

[KenC]

check the drain in the engine compartment for clogs. are the weep holes in your rockerpanels completely open?