Please do not buy a 4WD Vitz, they aren't meant for ours roads and they are quite fuel-thirsty as compared to the 1.0L and 1.3L front wheel drive variant(s).
They cost quite less as compared to other variants as well, a good amount of vehicles which are currently being imported are 4WD/AWD some of them include Corolla Fielders, Vitz, Belta's, Premio's and so on. So, before buying one please check it throughly.