I have a mid-size SUV but no rear-a/c. I live in TX and it gets HOT during the summer (current high is 101 today w/ about 85% humidity). I didn't think about how the passengers wouldn't get much air flow when I bought it, but now I feel so bad for my girls when I see them sweating even though my a/c is on full blast.
DH has a full-size SUV and his has rear-a/c. It makes such a difference!