Depends on the dealership. An honest, well run dealership will remove sold vehicles overnight. Some, however, notice a car that drives a lot of traffic to their website, then keeps them listed for a few days/weeks after the sale. It's just a bait and switch. You call/come in on a car, get to the dealership and miraculously it sold earlier that same day, but they have another, similar, car for you to look at. They'll even get you a good deal due to the inconvenience (IE: another way to get you to sit down and show you numbers).