Wow you sure you have the right seats in there? And face palm at steering wheel height. If you want to lower it 20-30mm then you will have to go side mount like v28 said. That's basically on the floor pan.
I had a1rm on the gtr at gp circuit with rs3's. They did OK to stop the whale. I'll be doing brabham on the 11th with these forza fp3 pads. They did great at wakefield. Now let's see if they can hold on at eastern creek.