[Boatanchors] Partially Off Topic Question

[Jack Antonio]

When did American automobiles go from a 6 Volt system
to a 12 V system?

I have a 52 Ford car radio which is 6 V, and I know
that by the time I was aware of such things in high school
in the mid 60s, all the family's cars were 12V, but when
did the change occur?

Was it an all at once starting with a given model year?

Were 12V systems optional, becoming standard at some point?

This was prompted by some idle thinking about using the 52 Ford
car radio as a basis for a simple cheap ham receiver, by adding
a BFO and a converter front end, a project that I may explore one
of these decades.

Thanks

Jack Antonio WA7DIA