things we hang off the rear view mirror, seem to be generally regional.

In Hawaii, when I lived there in the first half of the 90s, it was Ikaika helmets

High school graduate tassels seem to be mid western

On the East coast, there seem to be a lot of small Puerto Rico flags, in San Diego, it's Mexico flags.

In the retirement communities, it's disabled placards, 

Fuzzy dice, 

Around the hospitals, it's employee ID parking tags

the pine tree air freshener, dream catcher, and Buddy Jesus are not regional, just ubiquitous