Dear Fellow Prius owners: This is a long posting, but worth your time to read: We own a 07 Prius which is garage-kept and driven daily by my wife. We recently have noticed an offensive odor of mold coming from the AC vent whenever the car is first started (AC is first engaged). This is a common Prius problem, and many other owners are reporting on this problem - just search on "mold" and you will see what I mean. So, we made an appointment with our local dealer to get this problem addressed under warranty, even letting them know in advance WHY we were coming, as we believe that this is a valid and common warranty issue for any new car, no matter who makes it. (To be clear, this is mold, not mildew (which occurs on fabric) and it is caused by a design flaw in this car, and is not a naturally occurring problem, as your dealer may have told you.) At first, We got nothing but excuses from our dealer. Also, they denied coverage under the vehicle warranty, too, so we ended up paying to have them clean the evaporator (cooling) coil for this warranty problem. Now, I have about 15 years experience as an engineer working on commercial HVAC systems, and I do know a good bit about how AC works and about mold abatement. Having mold in your car is unacceptable and can cause health issues, such as headaches, fatique and other allergic or sensitivity responses. This is true for your home or office, just the same as for your car. But, our dealer's position is that: 1) this is not covered by the warranty, and 2) this is a common problem occurring with other makes and models of cars and 3) we can clean the coil for you and you need to run the car AC on outside air, rather than recirculated air (which apparently is the default setting). All 3 of these positions make no sense to me, #3 in particular since we live in a very humid climate where the O.A. humidity is often higher (80-95%) than in other locales. Again, the problem here is moisture buildup on the coil, or in the coil drain pan or drain line, or a blockage or buildup in the drain line, but in general, any of these issues would still constitute a design flaw or defect in the car itself, and therefore should be covered by the car warranty for the 1st 3 years or 36,000 miles. So, I escalated my concerns, in a polite fashion to Southeast Toyota Distributors, the company that runs all 169 dealerships in Florida, Georgia, and other states. The rep I spoke with WAS VERY AWARE of this issue, as they are based in South Florida, where the problem is EVEN MORE PREVALENT. Apparently, they are using a product called Baczymes for control of the mold on evap coils, which sounds like they are trying to mask or inhibit the mold growth, rather than FIXING THE PROBLEM. While the rep was polite and promised to call my dealer, and call me back, I am still out some $$ for a warranty problem. And, the callback has yet to take place. So, I have now contacted Toyota Corporate directly and asked them to respond to this issue. They opened a Case for me on this issue. Now, I am asking the rest of you with this problem to do likewise, to use the power of the Internet to let Toyota know that there really is a design defect, a design problem in later model Priuses and that there is an issue with this mold smell that needs to be addressed and there needs to be a TSB issued (Technical Service Bulletin) about this. (At present, there isn't even a TSB on this problem.) All you have to do is call Toyota Customer Service's toll free number and report that you are also having this same problem - it takes about 2-3 minute to do that. Here is the number to call: 800-331-4331. There is power in numbers, folks. The first step is to get TOYOTA to recognize that THERE IS A PROBLEM HERE. In the meantime, some of you have posted some wonderful ideas about how to deal with this problem. These include: 1) running the fresh air fan for 2 minutes before shutting off the car, 2) running the AC in non-Recirc mode on Outside air (which drastically reduces the cooling efficiency on hot days in Florida, folks) 3) running the heater before shutting off the car, and 4) using various non-bleach anti-microbial foaming cleansers to kill the mold and/or inhibit the growth of mold, (which is what we paid the dealer to do today). 5) Another solution that has not been mentioned is to replace the evap coil with a Teflon coated evaporator coil. This is a common practice with indoor AC systems that have problems with mold growth, such as TRANE variable speed AC units. In any case, the responsibility for SOLVING this problem lies with Toyota, and the financial burden should not fall upon the consumer to pay extra for a mold-free AC system - we should not have to do that, and we should not have to put up with mold in our cars either! Think about it - do your other cars spew out mold?? I have owned Hondas, Fords, Subarus and now an Isuzu in Florida and never had this problem before. So, it is a uniquely Toyota problem and it is Toyota's responsibility to get this addressed. Their $100K engineers need to go back to the drawing board on this one, folks. In any case, if you are willing to call Toyota and report this problem to the Corporate call center, we can get some momentum going on this, as it appears there are many people reporting this same problem. You paid a lot for this little car - and we love our Prius, as no doubt you do - but you don't have to put up with factory defects! Again that number for Toyota Corporate Customer Service is: 800-331-4331.