Just a tip.

My 9N3 polo was missing the plastic cover on the rear wiper, the part that goes over where the spindle/bolt is.
It turns out the part from a MK5 golf or similar aged VW fits.

I found this by going to the local car scrapper/recycling place.

Seems that there are two different sizes, and the 9N3 needs the larger one if you ever compare them side by side.

Handy if you are seeking this part, especially if you want it to colour match as buying new you would need to replace the whole arm otherwise they would not match due to sun aging/fading.