Browsing the internet I found a retro GPS system that looks period correct to go with our MGTDr’s.
It was very High Tech for the 1930’s.
Bill
This in-car navigation system sported a scrolling map setup,
the map was actually wired to the car so that the map would
scroll at a speed that matched the speed of the car???s movement.
Far from today???s GPS gadgets that track your movements from
space, this 1932 invention required the driver to pull over and
reload the map if he changed routes or turned. Still, it was a novel
invention in a time when a huge map unfolded on the dashboard
was the previously highest-tech navigation method available.