I don't understand how this got in cars to begin with, nevermind become mandatory. Invent thing, fund some studies that show a statistically significant safety

I don't understand how this got in cars to begin with, nevermind become mandatory. Invent thing, fund some studies that show a statistically significant safety improvement. lobby rule- and law-making bodies to make it mandatory. If anyone declines, run a PR campaign saying 'Jurisdiction bureaucrats/Obstructive Lawmaker want to KILL YOU & YOUR FAMILY.'