Mike's right in a way. Corner weighting a car is a long tedious setup process. While you can almost always weigh your car at a big event and you will get the corner weights, there is not enough time to make adjustments and reweigh repeatedly. But using the scales at a big event will give you your corner weights and you can decide if you need to make big adjustemtns to get even crossweights (that's what we do when we corner weight a car. We try to get it so that the Left Front + Right Rear = Right Front + Left Rear )