It helps if your a large kinda person yourself, Ive had bums come over by my truck look at me and go, I DONT NEED TO BOTHER HIM....But a tire knocker, taser, can of wasp spray, Mace, or Hair spray and a lighter might go a long way to convincing someone whom might be threatning that you mean business. When approached by these folks you have to be nice but firm, dont negotiate, dont converse, make the point you have no money or DONATIONS and they need to move on, if they dont, Drive away, if they persist call a cop.....if theres no cop and you must make a stand, dont put yourself in a position where your vulnerable. Get out with Maglite or tire thumper in hand on your shoulder ready to strike, keep space between you and them, if they rush you grab there collar, place one leg to your side and throw them down to the ground. CALL 911 BEFORE you have to do this....Ive had guys come up and look at me and decide they were better off just moving along, Work from a position of strength, learn some simple judo throws, or if worse comes to worse the eye gouge is a good move, a thumb stuck hard into anyones eye will back them right off and let them know you mean business. Worse comes to worse BITE THE EAR....Listen when it comes to me or them,,,they arent going to enjoy what I do and its not gonna be a love tap....MY VERY LAST RESORT WOULD BE A DEADLY WEAPON....a bum can recover from his eye getting gouged, and hell think twice, but shooting them when all they really want is a free bottle of wine or drug of the day might get you some serious issues as said before, Now if someone broke in my vehicle and got inside with me, they would die, plain and simple, I would not hesitate to take that life knowing what they might do to me or my loved one....BE SAFE