@Ben but if the AC is installed with dash level and foot level where you can choose the mixture you get to have nice cool air coming from under the dash which keeps you cool and it flows up to your body and face, even in stop and go traffic, when it is scorching. When you get tired of the sun on your head, you close the top, and if your window is a zippered back window you get to drive with a canopy so to speak with AC and then finally you can close the back windows and side windows and be in a sealed AC compartment. Ah, the joys of roll up windows and AC in an IM 
Just saying, there are lots of possibilities.