You know I never took the crossbars off, so I thought that they just bolt in and if you loose for bolts they are moving, but if you take them out, they will fall of. As you described, probably you're right. I just checked mine 4Runner and found that the ends of the rails are closed by plastic covers, so they have to be removed. I tried one at the rear and it pulled off. Looks like it has some sort of fasteners. I also unscrewed two bolts from the bottom of rails near that cover. May be it helps you. I didn't try to remove the crossbars, but it looks like a solution. I know that someone in this forum has