Well, in case anyone has these cars or ones like them, the windows are part of the roof. They have little wedges molded in, 2 per side, one front, one rear, that lock into a window frame. All you have to do is gently push those in on both sides (start on one end, then go to the other) and gently lift off the roof. Near impossible to figure out. BUT-i did fit an old postwar whistle inside that fits. Bought another car like it to have a non molested one to go with the set but it does now have a whistle with the ever so hi tech sound of steam.