Watch as, once the van’s front end hits the wall, the inertia of the pallet full of concrete sends it careening into the back of the front seats. The seats, the dash, and especially the dummies wind up pretty much obliterated. This scene is almost hard to watch, even though I know it’s just an artificial human:

Screenshot: Dynamic Test Center/YouTube

Dynamic Test Center has a number of other fascinating videos of loaded-up vehicles crashing. I myself have always been curious about such crash scenarios, but have never actually seen footage of any testing. Like, here’s what happens when a flatbed truck loaded with a car crashes into a barrier:

And here’s a wagon running into a trailer being towed by another wagon:

The main takeaway is that adding a ton of weight that isn’t rigidly mounted to your car is not a good thing for crash protection. I myself have a ridiculously heavy front axle in my Holy Grail Jeep Grand Cherokee. I should probably take that out if I want to avoid a knuckle sandwich (get it, because the axle has knuckles attached to it, and a knuckle sandwich is...nevermind).