Believe the problem is that the molding is slightly stretched when installed, then shrinks a little. I took out the bottom screw, pushed the molding up as far as possible, essentially putting the molding in compression, then installed the bottom screw further up the track to hold the compression. Small gap at the bottom of the track (hardly noticeable). Also,my unit is white so no paint line-up issue. Has not been a problem since - about three years, I think.
2012 Solera "S"
Calif SF Bay Area