Side/rear Glass problems of the 2011 Chevrolet Silverado 1500

Conditions: heavy misting rain, 32 deg f, lowering temperature, daytime. This is to report a design defect of the windshield defogging system. The defogging system operated as designed. There was no failure of the equipment. When the windshield defogger is selected this vehicles system automatically sets to outside air and turns off the airconditioning conpressor at 32 deg f and below. On December 6th while driving during misting rain at slightly above freezing with the temperature slowly lowering I experienced a rapid and serious problem clearing the windshield of mist on the inside surface of the windshield as well as all other glass surfaces when the temperature fell below freezing and the airconditioning compressor cut off. Despite using the windshield defogger at the maximun heat and fan setting I was forced to pull over to the side of the road because I could no longer see well enough to drive safely. Selection of windshield defogging mode actually worsened the problem initially. I believe that the design of the system creates the potential (and in this case actual) danger of rapid loss of visibility to the outside of the vehicle with the possibility of a loss of effective control.