Will this work with an aftermarket rear bumper or only the factory bumper?

This bar is engineered for the factory rear bumper assembly. If you're running an aftermarket bumper, verify mounting points align with stock attachment locations before purchasing.

Does this require any drilling or modification to install?

No — it bolts directly to factory mounting points. No drilling, cutting, or structural modification needed.

Should I prime or paint this before installing?

The bar ships ready to use. Paint is optional depending on your preference for finish and corrosion protection. If painting, degrease and sand lightly before applying primer and topcoat.