what is wrong with your rear window???
you wrote Only a few of the lines in my rear window... and if the second part of this sentence had to be: ...do defrost and the other lines are not doing anything at all anymore, you can save yourslef some money. It is possible to repair these lines there where they are broken/interrupted.
There was a post/thread about this topic(this week) in the diesel section started by someone called silverbullet...
If you still want to exchange the rear window, I can give you a dutch indication...
with a minor 600+k