caster question

Agree with others that it's time to take the fish to a different alignment shop. -4° of caster is not good. I run +2° on both cars with all stock suspension components (shocks excluded). This setting raised steering effort and increased turn-in sharpness.

Before more alignment, check condition of upper and lower ball joints and bushings. I once chased what I thought was an alignment issue that turned out to be a dying ball joint.