2013 Lexus ES350. I found the front carpets WET in the car under the front mats with 23000 miles and still under warranty. Took it to Smithtowmn Lexus on Long Island New York. They could not find the problem and wanted over $5000 to repair the the problem, New Carpet, Labor and a process to kill the mold ($3000) that had started under the carpet. Lexus is aware of this problem and people that had this say that their dealer covered it under warranty but not mine. They have this part that they will install that keeps insects out of the air conditioner drain hose as a maybe problem solver called a Drain Hose Insect repeller (Arinix tip Toyota part # 87265-33010 ). I blew my top when they wanted $10 for the part, Are you kidding me, a $40,000 car under warranty and a soaked carpet and you won't even give me that. After my raise in voice they gave it to me.

Finally went thru insurance and had the car flatbedded to an Auto body (No interior in car because Lexus removed it which also cost me $516) that put in new carpet and sent the car to Servpro to get rid of mold with the same process as Lexus ($400). In the end 30 days later total with out car, $250 deductible and rental car costs we have car back and still don't know where the water came from.

Update from Jan 21, 2016: Car has been repaired. The body shop guy seems to believe that it was the air conditioner evaporator that was most likely clogged and had cleared itself because it was not clogged when he received the car but he cannot be sure.

So time will tell if it happens again.