You remember back in the dark ages when we hitched up trailers without the aid of backup cameras? One-shotting it a real achievement.

I bet those things have collectively saved a million man-hours by now in not having to hop out, check, hop in, move it the right two inches, hop out, check, hop in, back up three inches, hop out, check, hop in, pull ahead an inch, hop out, muscle it over a little, etc.