Being a car salesperson used to be easy. All your potential customers came the same way, through the front door. Sure, some would call, but that's fairly easy to handle. Now, everyone is online, checking review sites, Yelp, Facebook, and asking what their friends think. The simple truth is that when someone comes into a dealer or a car shop, they already know what they want, and they've formed their opinion online. In fact, if they didn't see you on…