1. Check the wiper arms themselves for proper curvature and tension against the glass.
My son recently purchased a 2013 Honda Fit. He noticed that the passenger-side wiper arm and blade kept vibrating when sitting at idle.
Air pressure kept it on the glass when using wipers at highway speeds.
Checking the arm, there was a large ding and a slight concave bend in the arm. Apparently the wiper arm was hit by road debris and bent slightly.
Gently bending the arm back to the original convex shape solved that problem.
2. Check to see that the wipers on the car are the original 'factory' lengths, and not too long or too short.
The wiper blades on his Fit were "whatever the neighborhood auto-parts store had in stock", rather than the 'factory' lengths, so there was an annoying 8" crescent-shaped streak in the middle of the windshield constantly left un-wiped.
Both wiper blades were too short. New blades of the 'factory' length quickly solved that problem.
3. I've used liquid Rain-X ever since I first heard about it in the 1980's, so I actually don't worry much about the condition of the blades until the rubber is falling off. I also use the Rain-X washer fluid year-round. That seems to make the liquid product applied to the windshield last about twice as long.
Now they have pre-moistened Rain-X wipes that are supposed to be easier to apply. I have not tried their wiper blades that have a wiping edge containing the product, in theory, providing a fresh application every time the wipers are used.
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