54 rattletrap..........thanks for that info, wondering if your TRACK is just open on one side- with no lip. I can understand that the rollers cant travel far enough to drop off of the ends, but newer cars I worked on had channels that had short turn downs so that once the roller was inserted at either end, it could NOT fall out. Maybe these do not have that extra length on the open side but the felt keeps the glass rigid enough to stay put.
