Will this plug directly into my car's wiring harness?

Yes. This mirror uses the factory electrical connector on your Mazda 3, so power and ground hook up without any splicing or adapters needed.

What prep work is required before painting?

The mirror arrives primed, so light sanding with 220-grit or higher and a wash will ready it for paint. Use your preferred automotive primer and color coat once prepped.

Do I need new hardware to install this?

Installation hardware is not included—you'll use your existing factory bolts at the OEM mounting points. Have those on hand before you start.