[sierrap615]

moisture buildup is a nautral byproduct of any A/C system, even your home A/C, some worse then others granted, but it is still normal. letting the moisture sit on the evaporator after shutoff causes microbial growth(mold). i just yesterday printed out a copy of a TSB about the same problem for saturns. their corrective procedure: remove any debris from the evaporator case, clean evaporator with disinfectant or cooling coil coating, and install delayed blower motor control module. cleaning the evaporator with disinfectant is very simular if not the same as infinity's verison, the common do-it-yourself verison is spraying Lysol in the vents. the delayed blower motor control module runs the blower motor after shutdown to reduce moisture buildup. maybe infinity doesn't have a delayed blower motor control module like saturn, maybe you could retrofit one to work. or the easy work around is to turn off the A/C but keep the fan on for the last few minutes of your drive before you shutdown the engine.