@ads678 – that box looks awfully like the tubs Royal Mail use for moving mail around in. The metal wheeled cages I used to move stacks of those around in would generate massive amounts of static electricity, the air would crackle and ll your hair would stand up when you walked past them; avoiding touching them was a good idea…
As I have a large bag in my car’s boot, with things like wellies and other stuff in, when I do shopping, like others have said, the bags go on the floor and/or the seats – I rarely have problems with them falling over.
Something else it’s worth having to help keep the bags upright, and in fact carrying them when loaded is a couple of these things, they’re brilliant and stop the handles cutting your fingers off!