I've managed more than a few car dealerships. I've seen salespeople take trade ins that replicate the original description and were driven by 19 year old church girls, and I've seen conservative V12 Mercedes traded by known hoodlums. Cars can be deceiving.
If they were gangsters, I don't think preparing for engagement in that manner is appropriate. Gangsters will likely have you outgunned, and they sound like they had you outnumbered as well. A poor tactical situation for you. I'd be inside, where I have better position, concealement, and cover. I'd also have a rifle instead of a pistol. Now the tactical situation favors me. If the circumstances seemed to merit action, I'd call the law, and hold a defensive position. If things got hot before the law arrived, a countersrike would be defensible in both the street and the courts, due to superior postion, firepower, and the fact I retreated to my "castle". On the other hand, a shootout in the street appears to be a no win situation here.
