This isn't new. Try the silicone spray anyway. It will "grease" up the track so that the window doesn't bind up in the first place. Unless of course it's so bad that you actually have part of the track loose, but that is, IMO, unlikely. When they start getting sticky (needing the silicone spray), they will start shifting and vibrating in the track until they will then act as you describe.
Look at it this way - a can of silicone spray is a simple and cheap fix. Isn't it worth at least a try to see if it will work before you take the panel off and start that mess? If it's as you describe, I'll bet that it will. Like I said, it's at least worth a try first. Maybe it will work, maybe it won't. Won't cost much to try it first!
-G
Gonzo,
I think you're 100% correct. It "vibrates" in the window frame too when raised and lowered. So the silicone spray is used in the upper part of the door frame where the window slides up into?
I also notice the window will rattle inside the door frame when raised about half way. Have you ever experienced that before? I would think something needs to be tightened or the weather stripping on the door sill needs to be replaced.
I would have thought the silicone spray was used INSIDE the door panel where the window regulator and the track that raises and lowers the window is located.
Is there a spray you recommend? Is WD40 an equivalent? I've never looked on the can to see if it's a "silicone" or petroleum base spray.
Thanks
-A