I have to admit that I have never driven in a car in a foreign country where the rules of the road are reversed.
If I did, I want want to get the Lanesafe. It is a device made to suction-cup to the windshield, and then project a green arrow or red X to remind the driver of what side of the road he or she should be driving on.
I’m not sure how to calibrate this thing so that the transition to British driving or American driving is clean, but it works both day or night. It is LED solar powered plus 12 volt in car charger, so it will always be up and running.
It is designed to “safely redirect your beam from oncoming traffic but do not block it. They not only stop dazzling oncoming traffic but safely redirect the beam to the correct side of the road whichever country you’re driving in. They will keep you safe and legal while traveling abroad”.
Now, if there was some sort of audio cue to drivers that would buzz if you are driving on the wrong side of the road. Perhaps if this thing was hooked up to a GPS, it could do that. I guess if the price were a bit more than $33, it might have other features.