Living in NM swamp/evaporative coolers are common on homes due to our low humitity here. They are useless on humid days and on the really hot days when the mercury hits triple digits and you really want to be cooler.
The latent heat of evaporation is how they cool, humidity does not allow for good evaporation. In high temps. they just plain struggle, I bought the biggest one I could for my small house, it still stuggles. I do have a small 12V one for RVs that I bought cheap at a garage sale, it works OK in the spring and fall.
Wild birds flock (pun intended) to the one on top of my house for H2O they perch on the side and drink off the pad. Most pads are Aspen shavings, paper or plastic. I no longer have my Macaw, but I can't see anything in the pads that would have harmed him.
I have to think that the H20 will splash as you drive.