I would just go to a dealer..because if it simply grease it should be cheap and you don't get the hastle....but it could be a motor going bad.
Great ideas guys. I will try the silicon this week!wesquire said:I went to the Acua dealer because I had a very slow dirver's side window. I thought the motor was going bad. It was especially slow when it rained. The dealer told me just to use some silicon lubricant available at hardwarre stores in a spray. I did and the motor was fine. It is now as speedy as all the other windows.
Very cheap fix