Water is somehow getting into my wagon, dripping from the upper right rear corner. I've taken the plastic molding down but because of the channel construction I can't find where it's coming from. It doesn't leak all the time when it rains. Sometimes I can drive around in wet weather for a couple of days, and then discover a small puddle of water in the back floor tray. Other rainy days, nothing. I have Eurorails, installed them myself, and was very careful to make sure there was mastic around the bolt holes when I seated the bolts. Is this water coming from farther up, like around the moonroof, and then down along the top right channel to leak out at the back? I thought possibly it was coming in through the hinge opening when I lifted the back door, but I checked and this doesn't seem to be the case. Am really frustrated and would appreciate any and all advice. Dick