[torginus]

They literally went from an exoskeleton based truck bent into shape to an aluminium truck whose interior frame shatters on impact instead of the panels absorbing the hit - so instead of having to replace cheap plastic trim and collision absorbing metal bars, the energy gets dissipated inside the (almost unrepairable) aluminium frame.

Additionally, they didn't manage to find a satisfactory solution to attach the steel panels to the frame so they glued them on.

I suspect the 'parts falling off' has something to do with the inflexibility of both materials as well as the different thermal expansion coefficients.

On normal cars, bodywork is either made of flexible plastic, or is attached via spring joints so that the vibration doesn't damage them - that's why you have panel gaps - so they can move around a bit.

If you fix them rigidly, they're going to shake off eventually.

[specialist]

A monocoque design could be really cool. Like the original Mini. https://en.wikipedia.org/wiki/Mini

Were I in charge, I'd've started with a kei car or city car. Or something (size wise) like Telo. https://www.telotrucks.com/

Definitely would not have started with an off-road vehicle.