I don't know, the boot (trunk) isn't that small, you could get a couple of big truck turbos in there.
More seriously, given the lack of space in the engine bay and the other work you would have to do, turbocharging a normally aspirated 500 is not really practical.
As above, technically yes, but the cost would be prohibitive you'd be better off just buying a Arbarth, or replacing the engine with one from said version, but again the cost and issues make it not worth it.