My offering here is like way too late to help you, but I'll make it anyway. Over the winter months (no really very cold here in Northern Calif. but in the 30-40F range), my windows, particularly the passenger window, operated very slowly. Before tearing into things, I fired some silicon spray( using a plastic spray-tube/straw ) down both window rails. The window operations improved greatly. and I haven't had the problem since.
Now, just today my driver's side window failed. It's down and can't get up. I suspect that the clip that people have referred to in this forum is the problem. I will be removing the driver's side door panel this afternoon or later this week, and I'll clean the window rails real well while I'm in there. The silicon spray worked well for the time-being, but now I'll correct the problem with a good cleaning.
A thought, however. Perhaps, the silicon spray is a good periodic maintenance practice. It lubricates well w/o a lot of grease that over time gets gummy.
