Glue should not be used on structural, quarters included, and I definitely wouldn't use it on a unibody floor pan. I don't know of any Oem that uses glue as a stand alone on the main structure, some trunk tubs and ancillary are . Steel bodies usually use weld-bonding and aluminum usually use bonding and rivets. I have seen it fail and have seen what happens to cars that have been wrecked that been repaired that way previously. I've seen many comebacks where glue was used, and 2 different companies deny warranty. Most of these adhesives have microspheres or some other method the keep every bit of glue being squeezed out so they make for very thick edges on an overlap, and the seams raise back up over time. Once the stuff is in between panels it makes it very difficult to go back drill and do a clean plug weld. The better body shops have moved away from the stuff. We even strength tested it vs plug welding under supervision of an I-CAR instructor. The glue pulled apart before the metal failed.
