it happens only when it rains. water drips in from under the dash board, only on the passenger side in front. cant figure out how it happens? any help will be appreciated

maybe it because it gets in through the hole where the windshield wipers are.. somaybe if you put something there it wont leak anymore.
i mean its worth a try,...

l could be the windshield seal that is really a large gasket of sorts but even more insidiously sometimes it is the door seal, the rubber gasket inside your passenger side door that is allowing water to get inside.