The mythbusters did an episode on "Spy car" stuff, and when I watched it years ago I noted it down because I thought it'd come in handy
https://www.youtube.com/watch?v=6zAMjkR1lrI
They made them out of hollow tubing, so the air flows out when the caltrop is in the tire and even if it flies out, the air will continue to leak. Only thing needed should be a decent vise and a spot welder, among other welding tools.
The mythbusters did an episode on "Spy car" stuff, and when I watched it years ago I noted it down because I thought it'd come in handy
https://www.youtube.com/watch?v=6zAMjkR1lrI
They made them out of hollow tubing, so the air flows out when the caltrop is in the tire and even if it flies out, the air will continue to leak. Only thing needed should be a decent vise and a spot welder, among other welding tools.