Since the time this vehicle was about 2 years old, the drivers side power window gets very sluggish doing up when it gets cold outside. The first time, I took it to a dealer who said the window track was dirty and they cleaned it. After that, it worked fine for a short time. The second time, a different dealer stated that the track needed to be lubricated, and, that was not covered under my warranty. However, they did not charge me as a gesture of good faith. The problem is still there, but, right now I am in Florida and with the warmer weather, it does not happen. My question is, why does it only happen to this window and not to any of the other three. Candidly, I believe there is a problem with the design or mechanism for the drivers side power window.