Shoulder belt mounting is also critical. Ideally they should be mounted at the same height as the drivers shoulders. This is tough in an attv where the frame is the only rigid point. Shoulder belts mounted higher allow the driver to raise out of the seat in a frontal impact, and belts mounted lower than shoulder height can cause spinal compression in a crash.
I won't argue at all on the 120 wall thickness, and as I said it is just food for thought.
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