I was wondering if anyone knew if the outer belt windowstrip that has the felt lined on it needs replacement when the felt is worn down. It's the windowstrip that touches the outer part of the window when it rolls up and down. Is this even necessary or is just the rubber part of the strip without the felt enough?

 

The rubber strip does most of the sealing. You can replace it if yours is damaged or you feel you need to.

 

So as long as the rubber part is ok, I don't need a new strip even if the felt part of it is gone?

 

Felt really doesn't have any waterproofing qualities. I'm pretty sure it's just there to keep the rubber from sticking to the window and prevent any etching onto the window from the rubber when it becomes stiff as it ages.