When I see the news, it seems like the people getting robbed are being stupid, usually. They go somewhere with 1500$ cash, in the middle of no where with nobody around to buy an item thats so cheap its too good to be true.
So far I haven't dealt with any sketchy people, but I profile.... Also if anyone seems like they don't have the funds (people between the age of 18-24 seem to have this problem mostly) I don't waste my time. So far, no one in that age range has the money so I don't waste time any more.
The best buyers are over the age of 28, 42-55 is best, buying a car for their kid. Or 28-35 buying a car for their spouse. In my experience, people with poor english, don't waste your time, they want to haggle like nobodies business.
Know the BOTTOM amount your willing to take and stick to it. Walk away if they start haggling after you've stated your bottom. And ALWAYS make sure its their time wasted if they want to be stupid. (Don't drive out of your way to meet them!!!! always meet at the closest safe place to your house, that way they have something to loose by driving 45 minutes back home with no car, and your out nothing)
As far as robbery, the biggest thing your going to get robbed of is your time showing the car if you don't filter out stupid people.