Broke rear glass guide adjustment nut...now what?

So, I had pretty bad wind noise in my 91 mr2, I did remove the side mirror and put some double tape in there as per some online tutorial (it didn't help at all, sadly); the noise was driving me crazy so I decided to remove the door panel and try to adjust the glass as well; just adjusting the front/ rear upper stops didn't help either so I tried to adjust the rear glass guide nuts and...broke the bolt in half (I hardly put any force on it ;/ ).

 
So...not sure how to fix that now ;/ (also, the wind noise is still there just as bad if not worse than ever)
What would you do?