You could very well have a drain plugged in the sunroof system. I have personnally seen this alot especially around this time of the year. Do NOT pour bleach down the drains, if it is clogged it will get into your car.....not good. The other option is the evaporator housing under the dash for your A/C system has a drain hose, that could be clogged. If it were the water would come out the foot well vent openings under the dash.
So how do I test for this? OK, for the sunroof test, open the roof, look inside and you will see the tracks the glass slides on(a alumin. color) and to the outside of that between the body and the slides is the sunroor tray. That is where you will slowly pour the water. Jack up the front or back of the car, or park on a steep hill, pour the water(no bleach please) into the tray, it should come out the body in the rear on either side of the trunk, and in the front just behind the front tire. It should come out at an even rate. My guess is it will trickle. You will then need to clear them. lol
The A/C hose you can have a shop lightly blow compressed air into the hose if water comes out then it was clogged. I do this at no charge. Let us know what you find.
