i've been looking into this myself,
i have a commercial, and the vinyl panels in the rear have the bolt holes blanked off with plastic caps and the seatbelt run aperture is there.
i'll pull the vinyl out this savvo and have a look to see if there is anything going on behind, if so looks like a simple job/swap from a donor.
I don't know however if there are any legal issues with installing sideways facing seats now....anyone?