Luckily you're not in Commiefornia. If someone had seen that in the back of your van, the panicked calls would have come into the PD and a 10 square block area would have been evacuated. They would bring in a robot to pick up the box and put it in a containment vessel and then blow it up with their own explosives. And, of course, you would be arrested and labeled a domestic terrorist. Of course, warrants would be obtained for your house to find all these grenades that you obviously must have secreted in various locations throughout your house and garage. Wouldn't matter that it was just a box.