4WD Yaris / Vitz questions

[Swing]

Okay, I didn't know it, but apparantly there are 4WD versions made of the first and second generation Yaris. They are called Vitz in Japan, and possibly the 4WD versions were only sold in Japan or parts of Asia.
So I don't want to talk about what somebody made in his shed, but what Toyota has produced.

But what I can see now is that there are at least two 4WD versions of the Yaris/Vitz. Both same to be the 1.3 engine instead of the 1.5

1st gen: 1.3 2NZ with manual transmisison:
http://www.toyodiy.com/parts/g_J_199...5-AHMNK_2.html

2nd gen: 1.3 2NZ with automatic
http://www.toyodiy.com/parts/g_J_200...5-AHPGK_2.html

I like the idea of a 4WD yaris as it allows you to put down some power. Of course, that's not a big deal with a 1.3 petrol engine. But you can fit the 1.5 1NZ with a supercharger or turbo kit.
You could even weld the transfer case, and make it into a rear wheel driver Yaris quite easily :) (just for the fun of throwing a rwd around the corner, although 4wd is safer and provides more grip in the end)

My questions:

1. How does the 4wd work? I would assume it is an open centre diff, as with any awd road car (so not like 4x4's). But I see in the parts system a transfer case that seems to have 1 set of pinion and rack. So the axle going through the transfer case always seems to power the rear axle (via prop shaft)?
Which would be strange, you need an open diff for road driving.

2. In relation to question 1, perhaps is there a way to engage 4wd if it is not an open diff? Perhaps there could be a difference between manual and automatic here.

3. I also don't completely understand where the transfer case is located. I would assume it is between gearbox and front diff, but does that mean that the location of front diff is different from normal fwd version? And so longer/shorter axle shafts?

4. I guess that the body is a bit different to make room for the propshaft and rear diff?