First check to see if there is a gap at the top between the seal and glass.My granddaughters cabrio had the same proble on bot front windows. I took the door panels and the windows are adjustable. The glass sets in two clamps that are adjustable and they had vibrated loose and let the glass slide down. Raised the glass up and tightened the clamps and adjusted untill I had the correct height and closed the gap between the glass and seal. No more water or air leaks.