Unhappylexusowner

This is my 4th Lexus. I have owned, a 2003 ES, 2006 GS, 2009 ES. I waited with enthusiasm to purchase the all new 2013 ES 350. I purchased one in August 2012, one of the earliest produced. In June of 2013, I began getting a mildew smell from my air vents when ever i turned on the A/C or just fresh air. I took it to my dealer and replaced the cabin filter with a new charcoal cabin filter. The problem did not go away. Again I took it to my dealer and was told that Lexus engineers say that you have to put the system into fresh air mode before you turn off the A/C system. I told them I have never had a car or known of any car that you have to do this. I asked where does it say to do this in the owner's manual? Again the smell did not go away. Was also told NOT to disinfect the system. They told me that this is considered regular maintenance. This is baloney. I wrote to the Eastern Regional Office asking them to swap my car for a new one and was turned down. My dealer tells me that their are many more cars with this problem. Lexus KNOWS that there is a problem but does not know how to correct it. How many others have the same issue with this vehicle? I am told that it is a problem on all 2013 models and Lexus will not take care and do the right thing. My dealer also told me that this problem has been corrected on the 2014 models showing me that Lexus is aware of the problem but will not do the right thing.