Rattling of the front wiper linkage (Solution)

Observed in the Polo 9N; may also occur in other models.

The rattling noises (even when the wiper arms are raised) seem to indicate an imminent failure of the front wiper motor. In milder cases, the noise is only noticeable when the engine is not running.
Characteristic feature: The speed of the rattling changes slightly in sync with the wiper's movement cycle, even when the wiper motor is running at a constant speed.

Cause:
The rubber seal between the wiper linkage and the lower connecting rod does not slide continuously on the rotating metal surfaces; instead, it jumps forward in small increments every few degrees, producing a rapid sequence of short squeaking sounds.
These sounds cause vibrations in the wiper linkage and surrounding metal parts, which amplify and distort them to such an extent that they can create the impression of mechanical defects (e.g., rattling/grinding gears in the wiper motor).

Remedy:
Apply some grease to the rubber seal (difficult to reach; you may need to detach the connecting rods).
2. Ignore the noise, as no serious defects are expected.

Removing the cuff would also help, but the wiper linkage (on the 9N) is not completely protected from dripping water. Therefore, over time, dirt could get into the linkage bearings and accelerate their wear, potentially leading to the connecting rods falling off the wiper linkage.