Sidebar from the OP seeking a weapon/caliber for barrier penetration such as car doors and windshields and soft targets at 10+ yards. There have been suggestions for burly hand cannons, AR, AK, shotguns, etc. as "truck" guns. But what about the effect of muzzle blast, flash, concussion, and recoil when firing from _inside_ the vehicle? Just a thought here, and especially for the young lady who works the night shift at the hospital: Why not a simple .22 revolver? They are plentiful and cheap, easy to operate (point and click), and not devastating to the senses when fired from inside a vehicle. As for storage, a lockable glove compartment or center console would suffice, or lock it in the trunk if necessary. Simple, cheap.

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Tom in AZ
Respect the Dingbat