Dixon Miniatures has some gangster drivers and passengers shooting guns in its gangster range:
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Although they come in sets, the company might sell you individual drivers. IIRC, the Dixon gangsters are 25mm, or even small 25s, although labeled 28mm.
Warbases also has some civilian and military driver figures:
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and here:
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Albeit I think the Warbases figures are likely to be 28mm.
Old Glory Miniatures also has some gangster and police passenger figures in its 25mm Blue Moon Gangland figure range:
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Gangster and pulp gaming in 25mm was popular for a while about thirty years or so back, and so there may be more companies than I have listed who had gangster or civilian auto drivers that might suit your purpose, but the ones I've listed are the ones I remember. Patrick Wilson (the Virtual Armchair General) has rules and an extensive line of paper stock buildings designed for Chicago Roaring 20s gangster-type games, and so might be aware of some civilian driver figures I've missed-if you want buildings, have a look at his on his website.
And a google search (for example, 25mm driver miniatures) might turn up some 3d printed driver figures available through Etsy or elsewhere.
gets his hands on some fields and fences.