Rain leaking into car, any suggestions?
 

I just bought my used Buick from a private seller about a month ago. Since then it has rained a few times. Each time it rains, there is a huge puddle on the passenger side floor. Yesterday when it rained, I ran to my car to see if I could see where it was coming from. I pulled off the glove box and moved the mat. The rain seems to be coming out of the plastic blower. It was pouring out of there like a waterfall. I can't figure out where the rain is coming in from BUT I was wondering if this was a known problem (defect, known dry rotting of certain parts ect..) Any suggestions? Diagnosing a leak is hard because water can snake around places and follow things before it actually drips:confused:.
Thanks!