I must say my first thought was to question the bonding of the Optimum product to the trim. Has anyone got an MSDS for it - I could more accurately comment with that in hand?
Generally, the most advanced coatings out there are very surface specific. In order to form covalent or iono-covalent bonds, one needs the correct coupling agents. Look at the various surfaces one might encounter - glass (inorganic - silicates), metals, trims (misc plastics), clearcoat (organics such as urethanes, hybrid organic/inorganic, etc, etc). The chances are that if a product adheres to all of them that it may well compromise the ultimate strength of said bond. More than that, if a product is optimised to bond to any one (inorganics for instance), it will often not be optimal on others. Consider, for instance, paints (general). Many paints are great until you would try to apply to glass or bare metals. They will cover but they will not last.
We really need Optimum to comment on this and maybe tell us what tests
they have done which lead them to believe there is bonding to plastics
and how they have measured that it remains 'stuck' with time.