Powder coat or vinyl "wang skin" upgrades are strongly recommended. Otherwise, wings are shipped raw, and while aluminum does not corrode the same way ferrous metals do, your wing will get progressively uglier as it is exposed to the elements.
Wangs and Mega Wings are covered byWang Guarantee. Splitters, Sturdy Boiis, and air dams, based upon the nature of the use (and proximity to the earth), carry no warranty and are non-refundable. If you bolt these items to the car you own 'em.