Evaporative Cooler on the Roof??

Any of you "boys" remember the ones that used to hang off of a rear, side window? They were kind-a round and a couple of feet long? And also, do you remember the "Water bag" that we used to hang in front of the radiator and it would "seep" water and therefore, sort of put cold "moistured air" into the radiator which, in theory, would help cool it. Man, that was a while ago. Man I'm getting old.
Scott