We have a Sorento with rear A/C. There is a button that toggles it on and off. I was wondering about how this A/C operates. Are there two A/C compressors on the Sorento? One for Front and 2nd row, then a smaller one for the 3rd row since that one can be turned off and on independent of the front and 2nd row? When I have the front on, then switch the rear on, I don't feel any added draw of air pressure or cooling capacity from the front vents. It seems to me that they are two systems?