That overlay only shows up for me after I've switched to the LastPass keyboard and selected the password and filled in the box, too little way too late.
A company a friend of mine works for does something like this. You have a desk, at your desk is a laptop, monitor, keyboard and mouse. Your desk is yours to personalize and it's in an open area. Want a quiet room? There's a few dedicated working rooms for individuals or small teams, grab your laptop and move there. Work in an office but want the collaborativeness for a bit? Grab your laptop and move to one of the unused desks.
Sure, it involves investing in a space with lots of extra room, but they have been very successful in it so far for the last 5 or so years.
You have to start somewhere though, it can be a transition over time as well. Say a law was passed that all new roadside signs erected from date X will have both m and km, then at date y, years down the road, all new signs only list km.
For cars, just use the same dials and displays they use in Canadian cars, metric is the primary unit with imperial also shown, again, on new cars only, no need to retrofit all old vehicles.