Nissan Repair: late model nissan altima, nissan altima, heavy rain

Question
After a moderate/heavy rain my friends Nissan Altima smells like mildew. Any reason?

Answer
Jerry,

Check the carpets for dampness to see if the car has leaks internally.  A windwhield seal could be defective or if it has a sunroof.  Also, the drain on the airconditioner box could be plugged allowing water to get into the car.  That would be an easy fix if it is jus ta matter of unplugging the drain under the car on the passenger side.