Basically at a certain point on the window when I roll it down the thing makes a terrible noise. What do I have to do to the glass and/or rubber to get this to stop? It sounds like the glass is just making noise as it rubs against the rubber pieces, but it hasn't been an issue before.

Any tips?

 

Try running a a credit card between the glass and the rubber molding. Not sure if this will cure it but every once and a while I'll get a little piece of sand or rock in there and not only does it make a horrible noise but it can potentially scratch the glass.

If it's more of a sound from the rubber just "catching" on the glass, maybe you can try dressing the rubber with something (not sure what would product would be best here).