Check the rubber seal / window molding at the front interior of the window. I've replaced mine once already, and going back for another next week (goes back every week, for something, it seems).

They seem prone to buckeling (on mine at least), just a little bulge in the seal, like it just isn't on straight so it wrinkles a little. Nearly identical in both cases. You will know if this is your problem just by putting your finger on it. If you press the molding with the tip of your finger and the noise stops, then there ya go.

Also note: I have had the passenger door and window adjusted three different times now, as well. Each adjustment seems to last about a week and half - two weeks. They just don't seem to want to stay in alignment. (Pass door won't shut completely without MASSIVE force and / or window sits ontop the seal, not inside it.).

But, only the Passenger Side. Adjusted the Drivers once (first time they did the Pass) and its been great ever since. So I'm starting to think something isn't right with the passengar door (if it were both I'd chalk it up to the frameless windows, but its the least used side).