2000 Chevy Impala Wet carpet on passenger side after rain

This problem was noticed about six months ago and I have not been able to determine the cause.
We have owned the car since new (original owners) and is not garaged. The car is normally backed into the driveway which has a slight slope toward the street and this wet carpet condition had never presented itself in any form until recently.
The windshield was damaged and replaced about five years ago. Water leakage into the passenger cabin had never been a problem until about six months ago. The drain on thew air conditioner condensef has been verified to be clear and draining properly. We are stumped as to the source of this problem. Please help !