It seems as though all SUVs have one but no cars do (I think I saw one on an older Acura Integra, but that's about it.) Is there a reason for this? Aesthetics? There certainly doesn't seem to be a functional reason why it would be on one but not the other. (I don't think they should be added to cars -- I think they should be removed from SUVs.) If anything, the more vertical rear windshields of SUVs would allow rain and snow to fall off faster than on cars. What gives?