How do you keep emergency stuff from sliding around the trunk?

A collapsible crate worked great for my hatchback.

I just use a small plastic bin with a lid, but mine stays put because I wedge it behind the seat. Never had much luck with anything loose in a hatchback.

I keep a plastic milk crate back there. Not the fancy kind, just one I grabbed from the garage. It doesn’t match anything and looks dumb but it doesn’t tip. The trick for me was putting the heavy stuff on the bottom and the lighter junk on top, because when I had it the other way around the whole thing would lean and dump everything out on turns.

My personal preference is to keep the crate empty-ish so I can just toss the jumper cables in without playing Tetris. If it’s packed to the brim I end up digging anyway, which defeats the whole point. I also stopped trying to make it look neat. Loose stuff in a crate is fine.

Only downside is the crate itself slides a little on really hard turns, but nothing falls out, so I don’t care. Cheap and it works.

Loose stuff in a shallow trunk is always gonna slide, that’s just how it goes. I quit fighting it and screwed a couple of small eye hooks into the side panels, then ran a bungee across. Jumper cables stay put now and I can still yank them out one handed

I keep my emergency stuff in a soft-sided tote bag instead of a hard box. It squishes into the little gap behind the seats and doesn’t go flying when I turn. Plus I can just grab the whole bag if I need something. Simple but it works for me.

The thing that finally worked for me was ditching the box idea entirely and just using a small gym duffel. The shape of it molds to whatever space is left back there instead of sitting on top of the floor like a hard box does. When I turn, the bag kind of wedges itself against the side and stays put. It’s not bolted down or anything fancy, but it stopped the whole sliding around problem for me. Plus it has a handle so I can just grab the whole thing if I need to. Mine has a separate little pocket on the end that I keep the jumper cables in so they don’t tangle with everything else. Cost me nothing since I already had it in the closet. The shallow trunk thing is real though, there’s only so much you can do with limited floor space.