Just a little rain and you need the rear wiper...it's like the hind end operates as a vacuum...and if it's an unpaved road the rear window blacks out in a hurry.Keith said:I am new to the whole rear window wiper thing. I always looked at it as a cute little toy but not a useful feature. Kinda like the headlight wipers that were so popular a few years back. I have only 500 miles on my car but have been through a few rainstorms and so far the rear windows has not even gotten wet. Not sure how often or if ever I will use it. Would you want it running all the time? Maybe like stated earlier, it is only supposed to go so often.