As I'm driving on the main roads, going about 45-50 (in a 40-45 speed limit area, of course), I hear this occasional whistling noise from the driver's side, almost sounding like the window is a hair open. All windows & the sunroof are fully closed. Would it be time to replace the door seals or are the seals just dirty and need to be cleaned?

 

Since the driver door is the one mostly used, the top portion of the door gets a little "bent out of shape" from opening and closing from there.

The top portion of your door that surrounds the glass may be slightly bent inward towards the car with just a bit of muscle to solve the problem. Roll the window all the way down, open the door and brace it with your knee as you pull on the top portion of the door. Just pull hard and you will feel the metal bend ever so slightly. Now the door will seal much tighter and should fix the wind noise.

 

i used weatherstrip adhesive and resealed that portion of the door, whistling is gone now. the tube i bought was by 3M and costed like $5 or so from autozone