There is a fine line in excercizing caution (getting in your car and driving away - potentially being charged with fleeing the scene of an accident - a crime in a lot of states - not sure about AL) and getting out and talking to the person who caused an accident (potentially escalating a road rage situation).
Common sense is probably your best weapon. If the person is physically imposing to you and is angry. Getting on your cell phone with the windows rolled up and calling the cops is the best bet. If they get out and approach you and you feel threatened, getting out of there is the best bet. Then call the cops and report.
If possible walk to the service station cashier area and report the incident there. Obviously if late at night, safety should be your first concern.
Starting a firefight in the middle of a gas station (where smoking is dangerous) is probably not a good idea.
