Carbon fibre would be awesome - great idea. As far as the strength in rear end collisions is concerned, well the steel (I assume) panel might only be bolted down but those bolts are in sheer and the panel is in compression giving very high strength in the horizontal plane with little bending. Also when the steel does crumple, energy is absorbed which, unless you want to wear a neck brace for the rest of your life, (or worse) is worthwhile.
Once I get my car I’ll start pulling it to pieces (hey, it only cost $85k!) but I do that to any new car, and see what to work on first. Maybe the front (frunk) - gotta be loads more space there.
In the meanwhile, I’m tiling my garage floor to create a specific charging area!
Btw elsewhere on the forum I’ve seen debates around public charging vs home charging. With the price of electricity here (Sydney Australia) my first choice will be public chargers, which are largely free. Certainly the one at my local BMW dealer is, and it’s solar powered. And that makes so much more sense than using coal fired electricity from Energy Australia at home!