A few people have been asking what the sensor on the 2012 Camry Hybrid does.
This sensensor is monted to the left of the rear view mirror. It reasd temporature of the windshield and humidity. It sends a signal to the air conditioner. A humidity sensor is used in many Auto AC systems. This one is lte latest addition in improving comfort in the cabin.
I have over 100k on my 2007 Camry Hybrid. Great car and new one is even better.