water leaks in on passenger side

either your winshield is leaking or heater core if its coolant or a/c drain tube is plugged and the tray is overflowing. hard to say depending on how high the leak is.these are the only things there that could leak.

Do you have a sun roof?

I just bought a 2012 dodge ram 1500 and guess what its leaking at the same spot as yours so i decided to look into the problem myself i took off the side moulding that runs down the side of the windshield and then took the roof mouling off that hides the body seam and noticed that their is a crack in the seam the crack is finer than a peace of hair but water gets in runs between the roof and runs down the piler post just to say it gets the corner of the headliner wet