I have rented mini vans from Hertz before in the past- and needed to move a lot of computer equipment from one place to another. I have found they will use a thick black cable / wire to keep you from removing the seats in both SUVs and mini vans. I don't understand why they do this.

You might be better off renting a cago van from Ryder / Hertz Truck / or a local rental place that rents cargo vans. Some places also rent full size pickup trucks for moving things-