[thstone]

There is definitely moisture getting inside the car and condensing on the inside of the cold windshield during the night. The fix is to stop moisture from getting in and dry out the interior.

Besides the two drains under the clamshell, be sure to check the two front drains next to the battery in the front trunk. Those can get clogged and then moisture can get into the interior through the firewall access holes - thus creating moisture problems with the inside of the windshield.

Last, find a warm place (warm dry garage/sun during the day/etc) and open up the windows to try and let the interior moisture dry out of the interior.