[el ess A]

The trunk underside is bare right now and not on the car, with the latch, cover and all that removed. I'll try and take some pics tomorrow. There is NO direct access holes to these inner retainers. Maybe if you have extra long, and I mean extra long needle nose you may could reach them. These things act like a zip tie in a way. You put the insert in the hole, and the threaded stud would push down through the center of the insert, spreading out a couple of ratchet teeth that essentially let you push it in tighter, but won't let it come back the other way.

I'm thinking if I could somehow reach it with a hacksaw blade or curved pick I could somehow bend the tabs or break them. Real PITA to reach them from the bottom side.

Part number for the inserts is 22761970 in case anyone is going to need them. They're like nearly $4 list price each from GM.