There are a few things you need to know before putting your car on 4 jack stands. First, make sure that the car is level and that all four corners are lined up. Second, make sure that the jack stands are sturdy and have enough power to lift the car. Third, use a helper to help you lift the car off of the jack stands and place it on the ground. Finally, be sure to secure all of the parts of the car with screws or nails before leaving.