When you find people that are looking for cars what a great way to get the word out then by Instagram. You can take down their information when you get their number. If someone is just looking then you can give them your Instagram information and they can look through new cars that are on the lot right there. You can also update your inventory for people by posting that a car is sold.
This will also build their interest in coming in and buying from you. You can give a small credit for people that use your Instagram. You can say that they are getting a discount because you did not have the car long and they helped you keep your money out of advertisers hands, so they deserve a discount on the cost. Compared to if they buy another car. True in some sense but the car is gone.
If you are selling a car as the owner, what a great way to get it out to all your friends that you are selling a car. They can show it to someone that they know and they will help you push your old car out the door.