Cross Caster
WARNING: This page is about a different car, the 2014 Fiat 500e. However, it is still accessible from the selected car via links, so may be relevant.
Cross caster is the difference between left and right caster. To achieve the cross caster reading, subtract the right side caster reading from the left. For example, if the left caster is 2.5° and the right caster is 2.7°, the cross caster would be -0.2° (2.5 - 2.7 = -0.2).