Communication between neighboring drivers on the road is critical for safe and smooth driving. Drivers currently communicate by sounding horn or blinking lights, which sometimes is too coarse-grain to precisely convey the message, i.e., it is not apparent who the target and what the intent of the message is. Towards a better alternative, we explore the possibility of utilizing the smartphones of drivers to enable targeted communication between them. We propose a system, called DriverTalk, with which a driver can directly talk to convey messages such as you-are-blocking-traffic to the driver of the vehicle in front and do-not-tailgate-me to the driver behind. Furthermore, DriverTalk gives drivers the opportunity to seek and provide information as and when necessary during their driving. To identify the senders and receivers while exchanging messages, without an a priori knowledge about the drivers and their smartphones/vehicles, DriverTalk utilizes Visual IDs, i.e., the appearance images, of vehicles. Our evaluation shows that DriverTalk could deliver what a driver says to the target driver in about 1 second and with more than 95% success rate under various traffic conditions.