is caused by the airflow rather than the fan.Thanks. The problem is that to achieve any cooling effect on a hot day the rear fan has to be turned to fast and the narrow vents create a very noisy airflow. The front fan/airvents are noisy when on full but normally do not need to be run as fast as the rear. Also if you're sitting in the front the noise from behind the ear seems more irritating than fan noise from the front although this is just subjective. I really enjoy the *max button when entering the car on a hot day but sometimes worry about how much engine power it uses - do you happen to know?