nothing wrong with balancing the car left to right. front to rear is more of a tuning thing. weight in different spots can calm the car down and make it easier to drive or more aggressive. but you dont need a scale for that. you can start off with the standard weight. ballast behind the tower, 1/4 oz in each rear triangle and 1/2oz next to the receiver. If you need more steering some as 1/2-1oz in front of the servo.