Here you can see we are aligning the car. The red plates are the alignment plates. (That is why they have the degree'd angle gauge on them to set your caster with). The red alignment plates are sitting on top of some dark grey plates...our scales. You want the weight of each of your front corners to be the same (and, of course, you want the weights in the rear to be the same as well). If one corner is heavier than its corresponding side, it will have different traction than the opposite corner. So, for really accurate and cool alignments, you finely tune the springs by tightening or loosening them to get the weights equal.
