Hope this will help.
Remove the the centre head restraint. Fold the seat back down, and then operate the seat lock 'wheel', at the same time pressing down hard on the seat back, which will then compress onto the seat squab. The seat unit will then rotate to a near upright position, and can be secured to the passenger head restraint rod to keep it in position with the elastic and hook. It will be few degrees off vertical. I have just been and tried folding the centre on my Yeti, and this is as far as it will go without straining the hinge system.
I had a Roomster previously, and there was slightly more room behind the front seats, and no centre console, so the central rear seat folded up perfectly, in comparison to the Yeti - but I'd rather have my Yeti!!