You're putting yourself in a situation that you would not put yourself in without arming yourself.
I wash my car armed. I go into my front yard armed. I go to the grocery store armed. I do not intervene in armed robberies armed (or otherwise).
Let's back up, Brian.
What would YOU do if there was a suspicious vehicle parked in front of your house? Not what you think I should or shouldn't do. But what would YOU do?