This crops up every so often among all manufacturers, it's most likely the angle of the wiper blades to the windshield, you may have to twist the wiper arms to fix it. Pair of pliars, garden hose, 10 minutes to fix. My 1991 VW Jetta & the mother's 2002 Jetta did this, both had to have the arms twisted. The '03 ION's had a TSB on it as well but mine doesn't suffer from it.