I have owned a RX300 and now own a 2013 ES350. I took delivery of the ES in November 2013 and in May 2014 I began experiencing this problem. I had no problems with my RX. I live in FL and it is HOT 9 months out of the year being in the 90s for 3 of those months. I have taken it to the dealer. Both times they changed the filter to the charcoal filter and have "flushed" the system. The bandaid fix lasted about a week. I was told that because of the heat that all cars have this problem. This is the most ridiculous thing I have ever heard. I have NEVER had this issues with any car I have driven. I was also told that I should turn off the recirculated air before I get out and let the unit run for a few minutes before turning it off. This is supposed to enable the water to drain. This whole situation is unacceptable. Consumers do not pay the premium price for a "premium" vehicle only to have to deal with a smelly AC for the first 5-10 min of their drive. I have been told that they have ordered a new "cleaning system" for this issues and that my car will be the first to have it done once it comes in. I am not willing to settle and deal with this issue. I will be taking my car back to the dealer and documenting that it will be the 3rd visit for the same issue with no resolution. Then I will research my Lemon Law rights. Not a happy Lexus owner this time!