In the field of protection, there are generally 4 groups of products: wax, sealant, hybrid and coatings. These products can be combined, but with mixed results. Knowing what the properties of a product are will clarify the end result.
Not all coatings have enough effect on the oxidized look of UV-damaged plastic. Most dressing restore the look better, but don’t offer the protection of a coating. Combining these 2 seems illogical and difficult, but it isn’t.