I have a 12' GC and the I always thought the AC was weak but I found its all really in the positioning of the vents. I rarely have passengers in my back seat but when I have they have always said the AC was fine.Had some friends in the rear seat complaining about the air not working real well for them. I had them fiddle around with the vents until the cool air was hitting them where it made them comfortable. They said it was passable, but that they wished the airflow was a little stronger. Glad I don't have to sit in the back, I don't deal with heat very well.