Yeah, the biggest difference is between break strength and tensile strength. The metal will stretch providing resistance to the impact and absorbing it. The glass will just shatter.
I notice you failed to address any of my requests for you to back up your position with facts. You have a loose understanding of a lot of things which is why I will say my final peace and then leave you to your delusional ramblings and delusions of grandeur. I can find no support for your statement that they slid into a stopped vehicle at less than 35mph closing speed. If you have it please provide it, or stop claiming it.
This is the vehicle yes?
First, the roof structure has nothing to do with the front aprons and front bumper, both of which are completely collapsed and crushed. If this is what a Honda Fit looks like in front of the cowl after a 35mph impact into a stopped vehicle on a wet road which would provide less collision force as it slid away than I gotta tell you, there should be a lot more dead Honda Fit owners.
40MPH into a stationary object.
Watch the roof skin. Watch it flex and warp as impact energy is transferred around it through the pillars. This is why the roof panel came off when it was glued, not because it was directly exposed to impact forces, the STRUCTURE it was attached to transferred the energy away from the impact and the shear strength of glue is less than welds so it came loose. You're assertion is that that thin flat metal panel is what is is keeping the passenger cage mostly intact. That the A pillar (windshield pillar) made of boxed super high strength steel that buckled was bolstered by that thin piece of metal?
Also isn't it funny how that Fit looks a lot like the one in your example? The one that had a "low speed minor impact" looks a lot like one in a normal speed offset head on impact? Again, either your facts are off or there was a lot more shody repairs done to that vehicle than a roof skin replacement.
Parse? Seriously? Come on man, no one is impressed with your thesaurus use.
And it's not unfair to state that there are various levels of "structural" that you choose to ignore in an attempt to make your point (or to make yourself feel superior, it's kind of a toss up). You claim knowledge of repair service manuals and yet the data I posted comes from an actual body service manual, the heading for the roof section listed as Structural Outline........does not even deem to show the roof skin. No body repair estimating software lists the roof skin as a "structural" operation.
Again, the windshield is considered a structural part of the vehicle, without a windshield you can push on the upper A pillar and deform the opening. This does not mean it is the same as an impact bar, frame rail, or apron. The roof panel similarly provides shear strength but in no way is it the main function of the roof structure, especially when talking about rollovers which is what was being discussed.
I made a factual correct statement in regards to overall roof construction comparisons between standard roof and panoramic roof designs in the case of a roll over event. You have made no attempt to address or dispute my statements on these facts. Instead choosing to make up your own argument, present irrelevant examples that are clearly misstated as well and create strawman cases attributed to me again in some kind of need to feel superior. Just another internet Reddit warrior.