One engineer I spoke to about thus last year wanted a stack of work for it to pass. Installing a roll cage was one thing....but when he wanted to make a 'mock' van to simulate a side impact collision and then test it in a roll over accident, even he admitted its going too far and not worth the headache. It would end up costing almost 10K when all is said and done.
Maybe if 15-20 people were interested in it, they could financially contribute to the 'experiment'....but in reality I don't think it's worth it.....plus a sideways mounted seat looks kinda silly