My 4 month old T roc with just 2000 miles on clock had a really annoying wiper shudder at different speeds. I assumed it could not be the OEM blades with so little wear on them. I invested in some glass polish after watching various YouTube videos , with no improvement. The solution was in fact to purchase a new set of A622S Bosch Aerotwin blades. Instant silence , smooth operation after weeks of cleaning, changing wiper fluids etc etc.