I bought a pair (Bosch) that squeaked for two years before replacing them again (also Bosch). The second pair did not squeak at all. And my W124 windshield is FAR from blemish-free!

Perhaps the wiper inventory in some stores is a bit more aged than others?

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car