We are used to just folding the back seats and filling the boot. When we just had 1 dc we bought a roof box too as we could only fold part of the seat Now we have 2 dc and a bigger tent and more stuff etc etc.
Do you take a trailer? Starting to think it might be a good idea. We had one when I was a child but then our car was smaller, we only had a Maxi. Our car has a big boot but we don't camp light! 