I work at a shop and today same thing, 4 door integra, wet as hell, the shop tech that fixed the car couldnt find it, I found it and it was the sunroof drain tubes blocked up with crap causing the water to back up into the car, the trunk was so full of water it actually went into the back seat!!! And if your car doesnt have a sunroof then check the tail light seals, also a common problem spot. Where is your car wet exactly? and what year is it? Let me know and I will see if I can think of anything else it could be. Oh one last thing i just thought of, Check your cooland level, could be a heater core leaking on the floor, I have had a few cars do this to me. Good luck