mine was leaking water into the trunk. it had caused some rust along the bottom channel and had bubbled up some of the paint. the rust had to be cut out and new metal welded in. the problem was probably caused by the window removal and replacement about 10 years ago that wasn't done properly. evidently there is an art to installing these windows; the body shop that did this work had a specialist come in just to remove and install the window. you may not see rust in the bottom channel until you remove the window itself...good luck.