348 Window Gremlins

Hi everybody. I have been flogging my new to me Ferrari around the nice twisty country roads around here and have really developed an appreciation for it.Before I purchased it I noticed that there was a fair amount of grumbling about 348 power windows on the internet.My car's passenger window has two problems:The front corner rubber is torn and tries to fold around onto the wrong side of the glass and it refuses to go downward unless i tap on the doorpanel.I hope I can replace the rubber piece from a parts source.Is the refusal to go downward the result of a dead spot in the window motor brushes?The car has the window accelerator kit and has had the connections replaced according to receipts I have.The window's speed seems fairly quick.If there is any electric window Yodas out there I would appreciate your advice.Thanks.Jay