Two of my great grandfathers bought cars around 1915. One owned a plantation outside of Memphis. And the other a ranch in California. They didn't have electricity.
Not developed by my comment is in 1920 you didn't 'need' a car in cities. Since you had street cars. In rural/small town America cars were really useful but electric cars were a non starter.
I don't think you can really make any sort of meaningful conclusion from this - rural areas tend to lag in this sort of innovation.