Wayulll ... height is the kicker. The Chalets have two benches on the sides, above the wheel wells sideways, and can fit four adults fairly comfy-bly... but the Chalets also have more interior height =))
Some of the old Land Cruisers and Rovers have these 'troop seats', ya know, same idea. If you run topless it's fine ... with the top, I think the best you could do would be a small Jeepish seat in the back, facing backwards, back-to-back with your existing rear seat.
Or, as has been pointed out, this is why God invented the Suburban.
-- A