Aha! this is good to know! i wasnt looking to increase the stiffness, just maintain the current stiffness
but if removing these parts wont effect that then i wont be looking for a roll-cage
might be tempted by some Suspension braces though!
its funny how you notice even the smallest of weight saved! i dont know how much i will be saving with removing the rear seats and seatbelts etc... but i got about 35kg out of the car by removing the spare wheel, sub box, amp and some random junk and that was already noticable!