Do I need to drill any holes in my bumper to install these?

No. These vents mount at factory bumper attachment points. Reference your OEM bumper hole locations before installation to confirm alignment with your specific setup.

Can I paint these before bolting them on, or should I install first?

Install first, then sand and prep the surface before applying your chosen finish. This lets you mask off mounting hardware and ensures a clean edge where the vents meet the bumper. Test fit guarantees zero fitment surprises before paint.

Will these sit flush with the lower valance, or do they extend outward?

The N1 profile adds minimal extension to maintain OEM proportions while delivering that track aesthetic. Verify clearance against your bumper's lower valance before final installation to confirm fit with your specific bumper design.