Will this mirror work with my existing wiring harness?

This mirror uses factory connector points, so it plugs directly into your vehicle's OE electrical harness. No rewiring or adapter harnesses needed—just seat the connector and test the power and heat functions before final mounting.

Does the heated element work with any defrost setting, or only on full defrost?

The heating circuit is controlled through your vehicle's climate control. It typically activates when you engage the windshield defrost function, but exact behavior depends on your Optima's control module—check your owner's manual to confirm activation method for your model year.

Are all fasteners and gaskets included, or do I need to source anything separately?

The mirror assembly arrives complete and ready to mount at factory points. Gaskets and weather seals are built in. Fasteners for rocker mounting are not included—use your original hardware or equivalent hardware-store stainless fasteners rated for outdoor exposure.