I'm just trying to play devils advocate here, but I am considering if this were my mother, and she is naive enough that she might A.) be so scared, too scared, to risk folding that back seat down, or reaching for that release hatch in the trunk for fear of being killed instantly by supposed abductor, and
B.) she might not have even realized there was a release button for the trunk. Some people just don't pay attention and don't think like that.
Yes, there are some things that are hanky, but maybe she was knocked hard enough that she really was out for several hours, and maybe she came to when that phone started ringing. I'm just saying, everyone had jumped on the suicide bandwagon, but what IF there really is a perp out there that did this to this woman?
Just food for thought