The freedom of the road isn’t really free when there are kids in the back. Driving severely limits your power to discipline the kids, control the bickering, or even talk effectively. You can’t reach your kids. You can’t even safely look them.
That is, unless you catch their eyes in the rearview mirror. This tool, first patented in 1921, allows you not to cut people off but, just as important, it is a crucial means of communicating with your children. It might not seem like much but, well used, the rearview mirror can be a brutally effective tool.