Well, this now appears to be a common problem among 'early' 2007 RX-350 model as more people are experiencing white dust and moldy smell after two years of service. Lexus, as a company, needs to deal with this appropriately. From what I can tell, the dealership is doing their best to ignore or side step the problem. The one question that I have is....how do we know the problem will not reappear 2 years after the evaporator has been replaced? By that time, the warranty on the car would have expired. It would be quite costly to replace the evaporator again. Given that this could lead to critical health issues from breathing in the white dusts and potential lawsuit against them, they should consider a recall. I would advise anyone with this issue to call Lexus Customer Assistance directly to file a complaint and have them coordinate repair work with the dealership first. This could save you a lot of time and money.
Bottom line, I'm very disappointed with Lexus. For the price we paid, I do not expect to experience such issue in a luxury car. Would think twice before buying another Lexus. Good luck to all RX-350 owners.