Hi Jean,
you actually
have a few boxes: The fridge, a black box on top of the fridge, a box behind the fridge and also the blue suitcase.
A lot of your other stuff seems to more or less not fit in a box. So your setup is, let's call it "creative" but also uses boxes. There's really no other solution - except that you'd be putting up with a terrible mess in your car.
I found my boxes that I'll be using in the future here:
transportprofi24.com
They're pretty sturdy. And look at the prices: They're Euro boxes, which is a European standard and therefore faces competition. So there's no "
outdoor and adventure" premium on it, it's all industry and transport standard. A 30x40 cm box with a height of 32 cm costs 10,80 Euros, and if you add a pair of robust and foldable handles and a lid it's still just 18 Euros.
This is all configurable and doesn't cost a crazy 60 to 80 euros per box.There is one difference, however: If you want to transport a box outside (e.g. on a roof rack), then a more robust and rainproof version is advisable. However, the Euro boxes with lids can also withstand rain if it falls vertically. In a storm or on a roof rack @ 120 kmh, however, I would consider more robust solutions.
In the car, however, the Euro things are perfect. And as I said, you can even leave them outside in 'not so heavy' rain. That's enough for me.