RUST Rear window pillow ( pictures )

Noticed this days after buying the Bora

Can little plastic rubber things be bought from VW? why is it rusting just on this part of the window ;/

http://img.photobucket.com/albums/v3...0_1311-800.jpghttp://img.photobucket.com/albums/v3...0_1309-800.jpg

ive seen this loads in my work got no answer though sorry all i can tell you is that bar can be changed easly without takin the windows out if that helps

how much are they do you know

cheers