Yeah they used jeeps but for staff cars they used Fords, Plymouth, Packards and who knows what else.
I'm just trying to figure out what model specifically.
My research leads me to believe most were 1941 ( but not sure).
It says not standardized. So I guess whatever they could get at the time. 40-42 Plymouth Woodie without the wood was what the Navy used as a staff car, I know that for sure