Geo Metro rear windows, open or closed?
 

I have a '94 and was curious, do you think opening the rear windows, which just vent out an inch and a half would be benificial or harmful for mileage. Right now I leave my side windows 3/4 up to help with aero, but don't know if that vent will allow more air in than is going out or something along that line. Whatcha think?

Well, it's a matter of comfort. If you have those rear windows vented and the front ones up, you can set your heater on "Vent" and this will keep you cool on a hot day and keep the smoke out of your hair. Having those front windows up will save you in drag.

I wish my 98 model had those.