The front windows on my 2016 Holden Calais rattle badly when you close the door and the windows is down. How can this be stopped? The dealer was unable to help? I've had this car since new and it started six months after.
The widow is probably rattling in its channel, which should be obvious when you remove the door panel to check it. The dealer should be able to fix it, and since the car is in warranty it’s their responsibility to do it. Keep at them, if not take it to a body shop.