Not every type of stain responds to an all-purpose cleaner. Insects on the front bumper, salt ground into the bottom of the sills, mould on a soft top or fabric roof, tobacco smell in the upholstery. For those cases there are targeted cleaners that address the specific composition of the dirt.

A specialist cleaner isn't overkill. You save yourself the effort of repeated scrubbing with a mild cleaner that won't solve the problem anyway. The right formula works on the right chemical bond, and you're done before you know it.