> Seems a little like saying, you burn some gas and your car goes, and if it goes 80mph, that's just physics.

So, if you want to try to use this metaphor, the situation is actually a little bit different. Try this:

"Seat belts make it safe to go faster than 20 MPH, and tolerable to go faster than 80 MPH. Unfortunately, sometimes bank robbers use them while going faster than 80 MPH, so we have to ban seat belts entirely to prevent them from robbing banks."