Hi there
are these seats the 3 bench variety or the 2+1 bench, where the seat nearest the sliding door is able to tilt forward to access the rear. Either way I had the 2+1 variety which came as standard with my T5 and have to be located by the window for the pillar to attach the seat belt to.
Hope that is of use, I'm in the process of changing to a rail system to allow greater flexibility.