Leather conditioning seems to be a personal preference with most detailers but not customers. No matter the age of the leather, using a conditioner adds a richness to the color and tends to bring a fresh scent to the cabin.
Koch Chemie Leather Star Treatment Conditioner applies as any other conditioner does, using a process of shaking the bottle, working the product in either with a soft applicator after being cleaned or by hand. The product is left to work it's magic, and any excess is leveled out and removed with a clean soft microfiber towel or interior mitt after the product has dried. Expect a softening feel after application.