Do I need to wire this myself, or does it come with a plug harness?

This tail light assembly includes the internal wiring connections but does not include a pre-assembled harness. You'll connect it to your vehicle's existing tail light wiring using the factory connector—no soldering or custom wiring needed.

Will this mount to the factory attachment points without modification?

Yes. This light is designed for the factory mounting holes on your Sierra—it bolts straight in at the original points with no drilling or bracket work.

Does the lens come tinted or clear?

The lens assembly comes as a complete OEM-style unit with the red reflector housing built in. It's ready to install; no additional finishing or masking is required.