When I bought my 300E last year, I noticed that the driver's window would get off track whenever the door was closed with the window open. The glass would go behind the rubber seal and against the front of the door, and force me to pull the window back on track. Never got it fixed.
Over the past few weeks, the window has become stuck on those rare, cold Florida mornings. Gently pulling downward on the glass got it going without a problem. Again, didn't think much of it.
However, I ran into another more serious problem this afternoon. When the window was on its way up, it stopped about 1 cm from the top and gave a loud "clunk clunk clunk clunk" noise. After searching this site, it appears that I need a new window regulator. A few questions: should this be done professionally? Are the earlier problems related to my current problem? Also, I noticed that the rubber seal was worn down pretty good. Could this have been sticking to the window (and causing undue stress which led to these problems)?